Overhaul ez* family of plot functions. * scripts/plot/ezcontour.m, scripts/plot/ezcontourf.m, scripts/plot/ezmesh.m, scripts/plot/ezmeshc.m, scripts/plot/ezpolar.m, scripts/plot/ezsurfc.m: Redo docstring. Match function output names to docstring. * scripts/plot/ezplot.m: Add %!demo block with sinc function. Redo docstring. Match function output names to docstring. scripts/plot/ezplot3.m: Add %!demo block showing 'animate' option. Redo docstring. Match function output names to docstring. * scripts/plot/ezsurf.m: Add %!demo block showing 'circ' argument. Redo docstring. Match function output names to docstring. * scripts/plot/private/__ezplot__.m: Implement 'circ' option for ezsurf, ezmesh. Implement 'animate' option for ezplot3. Implement new algorithm for finding valid axis setting for mesh, surf, contour plots based on function gradient. Eliminate complex Z values along with singularities because these are not plottable by mesh, surf. Implement Matlab-compatible 2-pass approach to finding valid domain for plot. Use 500 points for point-style plot functions ezplot, ezplot3, ezpolar rather than previous 60 for a smoother plot. Use better regexprep() calls to format "pretty print" title string. Relax input checking and allow 3rd parametric function to be a function of 1 variable only. Clean up code and use Octave coding conventions.