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/libinterp/corefcn/strfns.cc	Tue May 12 08:01:42 2015 -0700
+++ b/libinterp/corefcn/strfns.cc	Tue May 12 09:22:01 2015 -0700
@@ -50,7 +50,7 @@
 matrices, or cell arrays.\n\
 \n\
 Arguments are concatenated vertically.  The returned values are padded with\n\
-blanks as needed to make each row of the string array have the same length. \n\
+blanks as needed to make each row of the string array have the same length.\n\
 Empty input strings are significant and will concatenated in the output.\n\
 \n\
 For numerical input, each element is converted to the corresponding ASCII\n\
@@ -181,7 +181,7 @@
 matrices, or cell arrays.\n\
 \n\
 Arguments are concatenated vertically.  The returned values are padded with\n\
-blanks as needed to make each row of the string array have the same length. \n\
+blanks as needed to make each row of the string array have the same length.\n\
 Unlike @code{char}, empty strings are removed and will not appear in the\n\
 output.\n\
 \n\