Add titles and clean-up plotting %!demos. * scripts/plot/area.m, scripts/plot/axis.m, scripts/plot/bar.m, scripts/plot/barh.m, scripts/plot/clabel.m, scripts/plot/colorbar.m, scripts/plot/comet.m, scripts/plot/comet3.m, scripts/plot/contour.m, scripts/plot/contour3.m, scripts/plot/contourf.m, scripts/plot/cylinder.m, scripts/plot/ellipsoid.m, scripts/plot/errorbar.m, scripts/plot/ezplot.m, scripts/plot/ezplot3.m, scripts/plot/ezpolar.m, scripts/plot/feather.m, scripts/plot/fplot.m, scripts/plot/hold.m, scripts/plot/isosurface.m, scripts/plot/legend.m, scripts/plot/loglog.m, scripts/plot/loglogerr.m, scripts/plot/mesh.m, scripts/plot/meshc.m, scripts/plot/meshz.m, scripts/plot/patch.m, scripts/plot/pcolor.m, scripts/plot/pie.m, scripts/plot/pie3.m, scripts/plot/plot.m, scripts/plot/plot3.m, scripts/plot/polar.m, scripts/plot/rectangle.m, scripts/plot/ribbon.m, scripts/plot/rose.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/sombrero.m, scripts/plot/stem3.m, scripts/plot/surf.m, scripts/plot/surfc.m, scripts/plot/surfl.m, scripts/plot/title.m, scripts/plot/waterfall.m: Add titles and clean-up plotting %!demos.