maint: Eliminate "(void)" in C++ function prototypes/declarations. * mk-opts.pl, external.txi, embedded.cc, make_int.cc, standalone.cc, standalonebuiltin.cc, BaseControl.cc, BaseControl.h, ButtonControl.cc, ButtonControl.h, ButtonGroup.cc, ButtonGroup.h, Canvas.cc, Canvas.h, CheckBoxControl.cc, CheckBoxControl.h, Container.cc, Container.h, ContextMenu.cc, ContextMenu.h, EditControl.cc, EditControl.h, Figure.cc, Figure.h, FigureWindow.cc, FigureWindow.h, GLCanvas.cc, GLCanvas.h, GenericEventNotify.h, KeyMap.cc, ListBoxControl.cc, ListBoxControl.h, Logger.cc, Logger.h, Menu.cc, Menu.h, MenuContainer.h, Object.cc, Object.h, ObjectProxy.cc, ObjectProxy.h, Panel.cc, Panel.h, PopupMenuControl.cc, PopupMenuControl.h, PushButtonControl.cc, PushButtonControl.h, PushTool.cc, PushTool.h, RadioButtonControl.cc, RadioButtonControl.h, SliderControl.cc, SliderControl.h, Table.cc, Table.h, TextControl.cc, TextControl.h, TextEdit.h, ToggleButtonControl.cc, ToggleButtonControl.h, ToggleTool.cc, ToggleTool.h, ToolBar.cc, ToolBar.h, ToolBarButton.cc, ToolBarButton.h, gl-select.cc, gl-select.h, qopengl-functions.h, qt-graphics-toolkit.h, qdialog.cpp, qfontdialog.cpp, qprintdialog_win.cpp, liboctgui-build-info.h, liboctgui-build-info.in.cc, color-picker.cc, color-picker.h, command-widget.cc, command-widget.h, community-news.cc, community-news.h, dialog.cc, dialog.h, documentation-bookmarks.cc, documentation-bookmarks.h, documentation-dock-widget.cc, documentation-dock-widget.h, documentation.cc, documentation.h, dw-main-window.cc, dw-main-window.h, external-editor-interface.cc, external-editor-interface.h, files-dock-widget.cc, files-dock-widget.h, find-files-dialog.cc, find-files-dialog.h, find-files-model.cc, find-files-model.h, gui-preferences.cc, gui-preferences.h, gui-settings.cc, gui-settings.h, history-dock-widget.cc, history-dock-widget.h, interpreter-qobject.cc, interpreter-qobject.h, file-editor-interface.h, file-editor-tab.cc, file-editor-tab.h, file-editor.cc, file-editor.h, find-dialog.cc, find-dialog.h, marker.cc, marker.h, octave-qscintilla.cc, octave-qscintilla.h, octave-txt-lexer.cc, octave-txt-lexer.h, main-window.cc, main-window.h, news-reader.cc, news-reader.h, octave-dock-widget.cc, octave-dock-widget.h, octave-qobject.cc, octave-qobject.h, qt-application.cc, qt-application.h, qt-interpreter-events.cc, qt-interpreter-events.h, release-notes.cc, release-notes.h, set-path-dialog.cc, set-path-dialog.h, set-path-model.cc, set-path-model.h, settings-dialog.cc, settings-dialog.h, shortcuts-tree-widget.cc, shortcuts-tree-widget.h, tab-bar.cc, tab-bar.h, terminal-dock-widget.cc, terminal-dock-widget.h, variable-editor-model.cc, variable-editor-model.h, variable-editor.cc, variable-editor.h, welcome-wizard.cc, welcome-wizard.h, workspace-model.cc, workspace-model.h, workspace-view.cc, workspace-view.h, build-env.h, Cell.cc, Cell.h, __contourc__.cc, __magick_read__.cc, auto-shlib.cc, auto-shlib.h, base-text-renderer.h, bsxfun.cc, c-file-ptr-stream.cc, c-file-ptr-stream.h, call-stack.cc, call-stack.h, debug.cc, defaults.cc, defaults.h, defun.cc, display.cc, display.h, dynamic-ld.cc, dynamic-ld.h, environment.cc, environment.h, error.cc, error.h, errwarn.cc, errwarn.h, event-manager.cc, event-manager.h, event-queue.cc, event-queue.h, fcn-info.cc, fcn-info.h, ft-text-renderer.cc, ft-text-renderer.h, genprops.awk, gh-manager.cc, gh-manager.h, gl-render.cc, gl-render.h, gl2ps-print.cc, graphics-toolkit.h, graphics.cc, graphics.in.h, gtk-manager.cc, gtk-manager.h, help.cc, help.h, hook-fcn.h, input.cc, input.h, interpreter-private.cc, interpreter-private.h, interpreter.cc, interpreter.h, jsondecode.cc, latex-text-renderer.cc, latex-text-renderer.h, load-path.cc, load-path.h, load-save.cc, load-save.h, ls-hdf5.cc, ls-hdf5.h, mxarray.h, oct-errno.h, oct-errno.in.cc, oct-fstrm.cc, oct-fstrm.h, oct-handle.h, oct-hist.cc, oct-hist.h, oct-iostrm.cc, oct-iostrm.h, oct-map.cc, oct-map.h, oct-opengl.h, oct-prcstrm.cc, oct-prcstrm.h, oct-procbuf.cc, oct-procbuf.h, oct-process.h, oct-stdstrm.h, oct-stream.cc, oct-stream.h, oct-strstrm.cc, oct-strstrm.h, oct-tex-lexer.in.ll, pager.cc, pager.h, pr-flt-fmt.cc, pr-flt-fmt.h, pr-output.cc, pr-output.h, procstream.cc, procstream.h, settings.cc, settings.h, sighandlers.cc, sighandlers.h, stack-frame.cc, stack-frame.h, svd.cc, syminfo.cc, syminfo.h, symrec.cc, symrec.h, symscope.cc, symscope.h, symtab.cc, symtab.h, sysdep.cc, sysdep.h, text-engine.cc, text-engine.h, text-renderer.cc, text-renderer.h, toplev.cc, url-handle-manager.cc, url-handle-manager.h, variables.cc, xpow.cc, __init_fltk__.cc, __init_gnuplot__.cc, __ode15__.cc, audiodevinfo.cc, gzip.cc, liboctinterp-build-info.h, liboctinterp-build-info.in.cc, mk-build-env-features.sh, mk-builtins.pl, cdef-class.cc, cdef-class.h, cdef-manager.h, cdef-method.cc, cdef-method.h, cdef-object.cc, cdef-object.h, cdef-package.cc, cdef-package.h, cdef-property.cc, cdef-property.h, cdef-utils.cc, cdef-utils.h, ov-base-diag.cc, ov-base-diag.h, ov-base-int.cc, ov-base-int.h, ov-base-mat.cc, ov-base-mat.h, ov-base-scalar.cc, ov-base-scalar.h, ov-base-sparse.cc, ov-base-sparse.h, ov-base.cc, ov-base.h, ov-bool-mat.cc, ov-bool-mat.h, ov-bool-sparse.cc, ov-bool-sparse.h, ov-bool.cc, ov-bool.h, ov-builtin.cc, ov-builtin.h, ov-cell.cc, ov-cell.h, ov-ch-mat.cc, ov-ch-mat.h, ov-class.cc, ov-class.h, ov-classdef.cc, ov-classdef.h, ov-colon.h, ov-complex.cc, ov-complex.h, ov-cs-list.h, ov-cx-diag.cc, ov-cx-diag.h, ov-cx-mat.cc, ov-cx-mat.h, ov-cx-sparse.cc, ov-cx-sparse.h, ov-dld-fcn.cc, ov-dld-fcn.h, ov-fcn-handle.cc, ov-fcn-handle.h, ov-fcn.cc, ov-fcn.h, ov-float.cc, ov-float.h, ov-flt-complex.cc, ov-flt-complex.h, ov-flt-cx-diag.cc, ov-flt-cx-diag.h, ov-flt-cx-mat.cc, ov-flt-cx-mat.h, ov-flt-re-diag.cc, ov-flt-re-diag.h, ov-flt-re-mat.cc, ov-flt-re-mat.h, ov-intx.h, ov-java.cc, ov-java.h, ov-lazy-idx.cc, ov-lazy-idx.h, ov-legacy-range.cc, ov-legacy-range.h, ov-magic-int.cc, ov-magic-int.h, ov-mex-fcn.cc, ov-mex-fcn.h, ov-null-mat.cc, ov-null-mat.h, ov-oncleanup.cc, ov-oncleanup.h, ov-perm.cc, ov-perm.h, ov-range.cc, ov-range.h, ov-re-diag.cc, ov-re-diag.h, ov-re-mat.cc, ov-re-mat.h, ov-re-sparse.cc, ov-re-sparse.h, ov-scalar.cc, ov-scalar.h, ov-str-mat.cc, ov-str-mat.h, ov-struct.cc, ov-struct.h, ov-typeinfo.cc, ov-typeinfo.h, ov-usr-fcn.cc, ov-usr-fcn.h, ov.cc, ov.h, ovl.cc, ovl.h, octave.cc, octave.h, anon-fcn-validator.h, bp-table.cc, bp-table.h, comment-list.cc, comment-list.h, filepos.h, lex.h, lex.ll, oct-lvalue.cc, oct-lvalue.h, oct-parse.yy, parse.h, profiler.cc, profiler.h, pt-anon-scopes.h, pt-arg-list.cc, pt-arg-list.h, pt-args-block.cc, pt-args-block.h, pt-array-list.cc, pt-array-list.h, pt-assign.cc, pt-assign.h, pt-binop.cc, pt-binop.h, pt-bp.h, pt-cbinop.h, pt-cell.h, pt-check.h, pt-classdef.cc, pt-classdef.h, pt-cmd.h, pt-colon.h, pt-const.h, pt-decl.cc, pt-decl.h, pt-eval.cc, pt-eval.h, pt-except.cc, pt-except.h, pt-exp.cc, pt-exp.h, pt-fcn-handle.cc, pt-fcn-handle.h, pt-id.cc, pt-id.h, pt-idx.cc, pt-idx.h, pt-jump.h, pt-loop.cc, pt-loop.h, pt-mat.h, pt-misc.cc, pt-misc.h, pt-pr-code.cc, pt-pr-code.h, pt-select.cc, pt-select.h, pt-spmd.cc, pt-spmd.h, pt-stmt.cc, pt-stmt.h, pt-tm-const.cc, pt-tm-const.h, pt-unop.cc, pt-unop.h, pt-walk.h, pt.cc, pt.h, token.cc, token.h, usage.h, Array-base.cc, Array.h, CColVector.cc, CColVector.h, CDiagMatrix.cc, CDiagMatrix.h, CMatrix.cc, CMatrix.h, CNDArray.cc, CNDArray.h, CRowVector.cc, CRowVector.h, CSparse.cc, CSparse.h, DiagArray2.cc, DiagArray2.h, MArray.cc, MArray.h, MDiagArray2.h, MSparse.h, MatrixType.cc, MatrixType.h, PermMatrix.cc, PermMatrix.h, Range.cc, Range.h, Sparse-b.cc, Sparse.cc, Sparse.h, boolMatrix.cc, boolMatrix.h, boolNDArray.cc, boolNDArray.h, boolSparse.cc, boolSparse.h, chMatrix.h, chNDArray.h, dColVector.cc, dColVector.h, dDiagMatrix.cc, dDiagMatrix.h, dMatrix.cc, dMatrix.h, dNDArray.cc, dNDArray.h, dRowVector.cc, dRowVector.h, dSparse.cc, dSparse.h, dim-vector.cc, dim-vector.h, fCColVector.cc, fCColVector.h, fCDiagMatrix.cc, fCDiagMatrix.h, fCMatrix.cc, fCMatrix.h, fCNDArray.cc, fCNDArray.h, fCRowVector.cc, fCRowVector.h, fColVector.cc, fColVector.h, fDiagMatrix.cc, fDiagMatrix.h, fMatrix.cc, fMatrix.h, fNDArray.cc, fNDArray.h, fRowVector.cc, fRowVector.h, idx-vector.cc, idx-vector.h, intNDArray.cc, intNDArray.h, liboctave-build-info.h, liboctave-build-info.in.cc, CollocWt.cc, CollocWt.h, DAE.h, DAEFunc.h, DAERT.h, DAERTFunc.h, DASPK.cc, DASPK.h, DASRT.cc, DASRT.h, DASSL.cc, DASSL.h, DET.h, EIG.h, LSODE.cc, LSODE.h, ODE.h, ODEFunc.h, ODES.h, ODESFunc.h, Quad.h, aepbalance.cc, aepbalance.h, base-dae.h, base-de.h, chol.cc, chol.h, eigs-base.cc, fEIG.h, gepbalance.h, gsvd.cc, gsvd.h, hess.h, lu.cc, lu.h, oct-fftw.cc, oct-fftw.h, oct-rand.cc, oct-rand.h, oct-spparms.cc, oct-spparms.h, qr.cc, qr.h, qrp.cc, qrp.h, randmtzig.cc, randmtzig.h, schur.h, sparse-chol.cc, sparse-chol.h, sparse-lu.cc, sparse-lu.h, sparse-qr.cc, sparse-qr.h, svd.cc, svd.h, child-list.cc, child-list.h, dir-ops.cc, dir-ops.h, file-ops.cc, file-ops.h, file-stat.cc, file-stat.h, lo-sysdep.cc, lo-sysdep.h, lo-sysinfo.cc, lo-sysinfo.h, mach-info.cc, mach-info.h, oct-env.cc, oct-env.h, oct-group.cc, oct-group.h, oct-password.cc, oct-password.h, oct-syscalls.cc, oct-syscalls.h, oct-time.cc, oct-time.h, oct-uname.cc, oct-uname.h, action-container.h, base-list.h, caseless-str.h, cmd-edit.cc, cmd-edit.h, cmd-hist.cc, cmd-hist.h, data-conv.cc, file-info.h, glob-match.cc, glob-match.h, kpse.cc, kpse.h, lo-array-errwarn.cc, lo-array-errwarn.h, lo-hash.cc, lo-hash.h, lo-ieee.cc, lo-ieee.h, lo-regexp.cc, lo-regexp.h, oct-inttypes.cc, oct-inttypes.h, oct-mutex.cc, oct-mutex.h, oct-refcount.h, oct-shlib.cc, oct-shlib.h, oct-sort.cc, oct-sort.h, oct-sparse.cc, octave-preserve-stream-state.h, pathsearch.cc, pathsearch.h, quit.cc, singleton-cleanup.cc, singleton-cleanup.h, str-vec.cc, str-vec.h, unwind-prot.cc, unwind-prot.h, url-transfer.cc, url-transfer.h, version.cc, version.in.h, cxx-signal-helpers.cc, acinclude.m4, main-cli.cc, main-gui.cc, main.in.cc, mkoctfile.in.cc, octave-build-info.h, octave-build-info.in.cc, octave-config.in.cc, octave-svgconvert.cc, shared-fcns.h: maint: Eliminate "(void)" in C++ function prototypes/declarations.