doc: Rewrite docstrings for most plot functions. Emphasize clarity, use common "voice", and increase density of seealso links. * doc/interpreter/plot.txi: Add @findex entries that were in xlim.m * scripts/miscellaneous/getappdata.m scripts/miscellaneous/setappdata.m, scripts/plot/allchild.m, scripts/plot/ancestor.m, scripts/plot/area.m, scripts/plot/axes.m, scripts/plot/axis.m, scripts/plot/bar.m, scripts/plot/barh.m, scripts/plot/box.m, scripts/plot/caxis.m, scripts/plot/cla.m, scripts/plot/clabel.m, scripts/plot/clf.m, scripts/plot/close.m, scripts/plot/closereq.m, scripts/plot/colorbar.m, scripts/plot/comet.m, scripts/plot/comet3.m, scripts/plot/compass.m, scripts/plot/contour.m, scripts/plot/contour3.m, scripts/plot/contourc.m, scripts/plot/contourf.m, scripts/plot/copyobj.m, scripts/plot/cylinder.m, scripts/plot/daspect.m, scripts/plot/diffuse.m, scripts/plot/ellipsoid.m, scripts/plot/errorbar.m, scripts/plot/ezcontour.m, scripts/plot/ezcontourf.m, scripts/plot/ezmesh.m, scripts/plot/ezmeshc.m, scripts/plot/ezplot.m, scripts/plot/ezplot3.m, scripts/plot/ezpolar.m, scripts/plot/ezsurf.m, scripts/plot/ezsurfc.m, scripts/plot/feather.m, scripts/plot/figure.m, scripts/plot/fill.m, scripts/plot/findall.m, scripts/plot/findobj.m, scripts/plot/fplot.m, scripts/plot/gca.m, scripts/plot/gcbf.m, scripts/plot/gcbo.m, scripts/plot/gcf.m, scripts/plot/gco.m, scripts/plot/ginput.m, scripts/plot/graphics_toolkit.m, scripts/plot/grid.m, scripts/plot/gtext.m, scripts/plot/guidata.m, scripts/plot/guihandles.m, scripts/plot/hdl2struct.m, scripts/plot/hggroup.m, scripts/plot/hidden.m, scripts/plot/hist.m, scripts/plot/hold.m, scripts/plot/ishghandle.m, scripts/plot/ishold.m, scripts/plot/isocolors.m, scripts/plot/isprop.m, scripts/plot/legend.m, scripts/plot/line.m, scripts/plot/linkprop.m, scripts/plot/loglog.m, scripts/plot/loglogerr.m, scripts/plot/mesh.m, scripts/plot/meshc.m, scripts/plot/meshgrid.m, scripts/plot/meshz.m, scripts/plot/newplot.m, scripts/plot/orient.m, scripts/plot/pareto.m, scripts/plot/patch.m, scripts/plot/pcolor.m, scripts/plot/peaks.m, scripts/plot/pie.m, scripts/plot/pie3.m, scripts/plot/plot.m, scripts/plot/plot3.m, scripts/plot/plotmatrix.m, scripts/plot/plotyy.m, scripts/plot/polar.m, scripts/plot/print.m, scripts/plot/quiver.m, scripts/plot/quiver3.m, scripts/plot/rectangle.m, scripts/plot/refresh.m, scripts/plot/refreshdata.m, scripts/plot/ribbon.m, scripts/plot/rose.m, scripts/plot/saveas.m, scripts/plot/scatter.m, scripts/plot/scatter3.m, scripts/plot/semilogx.m, scripts/plot/semilogxerr.m, scripts/plot/semilogy.m, scripts/plot/semilogyerr.m, scripts/plot/shading.m, scripts/plot/shg.m, scripts/plot/shrinkfaces.m, scripts/plot/slice.m, scripts/plot/specular.m, scripts/plot/sphere.m, scripts/plot/stairs.m, scripts/plot/stem.m, scripts/plot/stem3.m, scripts/plot/struct2hdl.m, scripts/plot/subplot.m, scripts/plot/surf.m, scripts/plot/surface.m, scripts/plot/surfc.m, scripts/plot/surfl.m, scripts/plot/tetramesh.m, scripts/plot/text.m, scripts/plot/title.m, scripts/plot/trimesh.m, scripts/plot/triplot.m, scripts/plot/trisurf.m, scripts/plot/view.m, scripts/plot/waitbar.m, scripts/plot/waitforbuttonpress.m, scripts/plot/waterfall.m, scripts/plot/whitebg.m, scripts/plot/xlabel.m, scripts/plot/xlim.m, scripts/plot/ylabel.m, scripts/plot/ylim.m, scripts/plot/zlabel.m, scripts/plot/zlim.m: Rewrite docstrings for most plot functions. Emphasize clarity, use common "voice", and increase density of seealso links.

--- a/scripts/plot/plotyy.m
+++ b/scripts/plot/plotyy.m
@@ -20,25 +20,28 @@
 ## @deftypefn  {Function File} {} plotyy (@var{x1}, @var{y1}, @var{x2}, @var{y2})
 ## @deftypefnx {Function File} {} plotyy (@dots{}, @var{fun})
 ## @deftypefnx {Function File} {} plotyy (@dots{}, @var{fun1}, @var{fun2})
-## @deftypefnx {Function File} {} plotyy (@var{h}, @dots{})
+## @deftypefnx {Function File} {} plotyy (@var{hax}, @dots{})
 ## @deftypefnx {Function File} {[@var{ax}, @var{h1}, @var{h2}] =} plotyy (@dots{})
-## Plot two sets of data with independent y-axes.  The arguments @var{x1} and
-## @var{y1} define the arguments for the first plot and @var{x1} and @var{y2}
-## for the second.
+## Plot two sets of data with independent y-axes.
+##
+## The arguments @var{x1} and @var{y1} define the arguments for the first plot
+## and @var{x1} and @var{y2} for the second.
 ##
 ## By default the arguments are evaluated with
 ## @code{feval (@@plot, @var{x}, @var{y})}.  However the type of plot can be
 ## modified with the @var{fun} argument, in which case the plots are
 ## generated by @code{feval (@var{fun}, @var{x}, @var{y})}.  @var{fun} can be
-## a function handle, an inline function or a string of a function name.
+## a function handle, an inline function, or a string of a function name.
 ##
 ## The function to use for each of the plots can be independently defined
 ## with @var{fun1} and @var{fun2}.
 ##
-## If given, @var{h} defines the principal axis in which to plot the @var{x1}
-## and @var{y1} data.  The return value @var{ax} is a two element vector with
-## the axis handles of the two plots.  @var{h1} and @var{h2} are handles to
-## the objects generated by the plot commands.
+## If the first argument @var{hax} is an axes handle, then it defines
+## the principal axis in which to plot the @var{x1} and @var{y1} data.
+##
+## The return value @var{ax} is a vector with the axis handles of the two
+## y axes.  @var{h1} and @var{h2} are handles to the objects generated by the
+## plot commands.
 ##
 ## @example
 ## @group