Use Matlab coding conventions for demos in plot/ directory. * contrast.m, axis.m, clabel.m, colorbar.m, comet.m, contour.m, contour3.m, cylinder.m, daspect.m, errorbar.m, ezplot.m, fplot.m, grid.m, hold.m, isosurface.m, legend.m, loglog.m, loglogerr.m, pareto.m, patch.m, pbaspect.m, pie.m, pie3.m, plot3.m, plotmatrix.m, plotyy.m, quiver.m, quiver3.m, rectangle.m, refreshdata.m, scatter.m, scatter3.m, semilogx.m, semilogxerr.m, semilogy.m, semilogyerr.m, shading.m, stem.m, subplot.m, text.m, title.m, trimesh.m, triplot.m, trisurf.m, uigetdir.m, uigetfile.m, uimenu.m, uiputfile.m, waitbar.m, xlim.m, ylim.m, zlim.m: Use Matlab coding conventions for demos so that compare plots scripts will function.

--- a/scripts/plot/pie.m
+++ b/scripts/plot/pie.m
@@ -74,14 +74,14 @@
 
 %!demo
 %! clf;
-%! pie ([3, 2, 1], [0, 0, 1], {"Cheddar", "Swiss", "Camembert"});
+%! pie ([3, 2, 1], [0, 0, 1], {'Cheddar', 'Swiss', 'Camembert'});
 %! colormap ([1,0,0;0,1,0;0,0,1;1,1,0;1,0,1;0,1,1]);
 %! axis ([-2,2,-2,2]);
 
 %!demo
 %! clf;
-%! pie ([0.17, 0.34, 0.41], {"Cheddar", "Swiss", "Camembert"});
+%! pie ([0.17, 0.34, 0.41], {'Cheddar', 'Swiss', 'Camembert'});
 %! colormap ([1,0,0;0,1,0;0,0,1;1,1,0;1,0,1;0,1,1]);
 %! axis ([-2,2,-2,2]);
-%! title ("missing slice");
+%! title ('missing slice');