maint: Remove unnecessary whitespace at end of lines. * libgui/Makefile.am, libgui/graphics/Canvas.cc, libgui/graphics/EditControl.cc, libgui/graphics/Figure.cc, libgui/graphics/MouseModeActionGroup.cc, libgui/graphics/annotation-dialog.cc, libgui/graphics/annotation-dialog.h, libgui/graphics/gl-select.cc, libgui/graphics/module.mk, libgui/kb-layouts/default.keytab, libgui/kb-layouts/linux.keytab, libgui/kb-layouts/vt420pc.keytab, libgui/src/m-editor/find-dialog.cc, libgui/src/main-window.cc, libgui/src/octave-qt-link.cc, libgui/src/octave-qt-link.h, libgui/src/shortcut-manager.h, libinterp/corefcn/error.cc, libinterp/corefcn/find.cc, libinterp/corefcn/gl2ps-renderer.cc, libinterp/corefcn/graphics.cc, libinterp/corefcn/graphics.in.h, libinterp/corefcn/octave-link.cc, libinterp/corefcn/quadcc.cc, libinterp/corefcn/strfns.cc, libinterp/corefcn/syscalls.cc, libinterp/corefcn/sysdep.cc, libinterp/corefcn/urlwrite.cc, libinterp/corefcn/utils.cc, libinterp/corefcn/variables.cc, libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/colamd.cc, libinterp/octave-value/ov-bool-sparse.cc, libinterp/octave-value/ov-classdef.cc, libinterp/octave-value/ov-re-sparse.cc, libinterp/octave-value/ov-struct.cc, libinterp/parse-tree/pt-arg-list.cc, scripts/audio/@audiorecorder/play.m, scripts/audio/wavwrite.m, scripts/general/cart2sph.m, scripts/geometry/inpolygon.m, scripts/gui/listdlg.m, scripts/gui/msgbox.m, scripts/gui/private/message_dialog.m, scripts/help/get_first_help_sentence.m, scripts/help/lookfor.m, scripts/image/imshow.m, scripts/io/strread.m, scripts/java/javamem.m, scripts/miscellaneous/dir.m, scripts/miscellaneous/edit.m, scripts/miscellaneous/genvarname.m, scripts/miscellaneous/gzip.m, scripts/miscellaneous/private/__w2mpth__.m, scripts/plot/appearance/annotation.m, scripts/plot/draw/colorbar.m, scripts/plot/draw/quiver3.m, scripts/plot/util/hold.m, scripts/plot/util/print.m, scripts/polynomial/mkpp.m, scripts/polynomial/polyder.m, scripts/polynomial/spline.m, scripts/polynomial/unmkpp.m, scripts/signal/arma_rnd.m, scripts/sparse/gplot.m, scripts/statistics/tests/t_test.m, scripts/statistics/tests/t_test_regression.m, scripts/strings/mat2str.m, scripts/strings/strsplit.m, scripts/strings/strtrunc.m, scripts/strings/untabify.m, scripts/testfun/assert.m: maint: Remove unnecessary whitespace at end of lines.

--- a/scripts/strings/mat2str.m	Tue May 12 08:01:42 2015 -0700
+++ b/scripts/strings/mat2str.m	Tue May 12 09:22:01 2015 -0700
@@ -27,7 +27,7 @@
 ## The precision of the values is given by @var{n}.  If @var{n} is a scalar
 ## then both real and imaginary parts of the matrix are printed to the same
 ## precision.  Otherwise @code{@var{n}(1)} defines the precision of the real
-## part and @code{@var{n}(2)} defines the precision of the imaginary part. 
+## part and @code{@var{n}(2)} defines the precision of the imaginary part.
 ## The default for @var{n} is 15.
 ##
 ## If the argument @qcode{"class"} is given then the class of @var{x} is