doc: Update more docstrings to have one sentence summary as first line. Reviewed plot/ and gui/ in scripts directory. * scripts/gui/errordlg.m, scripts/gui/helpdlg.m, scripts/gui/inputdlg.m, scripts/gui/listdlg.m, scripts/gui/msgbox.m, scripts/gui/private/__get_funcname__.m, scripts/gui/private/__uiobject_split_args__.m, scripts/gui/questdlg.m, scripts/gui/uigetdir.m, scripts/gui/uigetfile.m, scripts/gui/uiwait.m, scripts/gui/waitbar.m, scripts/gui/warndlg.m, scripts/plot/appearance/annotation.m, scripts/plot/appearance/axis.m, scripts/plot/appearance/box.m, scripts/plot/appearance/caxis.m, scripts/plot/appearance/datetick.m, scripts/plot/appearance/hidden.m, scripts/plot/appearance/legend.m, scripts/plot/appearance/xlim.m, scripts/plot/appearance/ylim.m, scripts/plot/appearance/zlim.m, scripts/plot/draw/area.m, scripts/plot/draw/comet.m, scripts/plot/draw/comet3.m, scripts/plot/draw/contour.m, scripts/plot/draw/contourf.m, scripts/plot/draw/isocolors.m, scripts/plot/draw/isonormals.m, scripts/plot/draw/isosurface.m, scripts/plot/draw/plotmatrix.m, scripts/plot/draw/quiver.m, scripts/plot/draw/quiver3.m, scripts/plot/draw/ribbon.m, scripts/plot/draw/semilogxerr.m, scripts/plot/draw/semilogyerr.m, scripts/plot/draw/sphere.m, scripts/plot/draw/surfl.m, scripts/plot/draw/tetramesh.m, scripts/plot/util/allchild.m, scripts/plot/util/ancestor.m, scripts/plot/util/axes.m, scripts/plot/util/colstyle.m, scripts/plot/util/frame2im.m, scripts/plot/util/gnuplot_binary.in, scripts/plot/util/hgsave.m, scripts/plot/util/im2frame.m, scripts/plot/util/isaxes.m, scripts/plot/util/isfigure.m, scripts/plot/util/linkaxes.m, scripts/plot/util/ndgrid.m, scripts/plot/util/pan.m, scripts/plot/util/print.m, scripts/plot/util/printd.m, scripts/plot/util/private/__add_default_menu__.m, scripts/plot/util/rotate.m, scripts/plot/util/rotate3d.m, scripts/plot/util/saveas.m, scripts/plot/util/struct2hdl.m, scripts/plot/util/subplot.m, scripts/plot/util/zoom.m: Update more docstrings to have one sentence summary as first line.

--- a/scripts/plot/util/ndgrid.m
+++ b/scripts/plot/util/ndgrid.m
@@ -19,12 +19,13 @@
 ## -*- texinfo -*-
 ## @deftypefn  {Function File} {[@var{y1}, @var{y2}, @dots{}, @var{y}n] =} ndgrid (@var{x1}, @var{x2}, @dots{}, @var{x}n)
 ## @deftypefnx {Function File} {[@var{y1}, @var{y2}, @dots{}, @var{y}n] =} ndgrid (@var{x})
-## Given n vectors @var{x1}, @dots{}, @var{x}n, @code{ndgrid} returns
-## n arrays of dimension n.  The elements of the i-th output argument
-## contains the elements of the vector @var{x}i repeated over all
-## dimensions different from the i-th dimension.  Calling ndgrid with
-## only one input argument @var{x} is equivalent to calling ndgrid with
-## all n input arguments equal to @var{x}:
+## Given n vectors @var{x1}, @dots{}, @var{x}n, @code{ndgrid} returns n
+## arrays of dimension n.
+##
+## The elements of the i-th output argument contains the elements of the
+## vector @var{x}i repeated over all dimensions different from the i-th
+## dimension.  Calling ndgrid with only one input argument @var{x} is
+## equivalent to calling ndgrid with all n input arguments equal to @var{x}:
 ##
 ## [@var{y1}, @var{y2}, @dots{}, @var{y}n] = ndgrid (@var{x}, @dots{}, @var{x})
 ##