Overhaul scatter family of functions * scripts/plot/module.mk: Remove unused function __color_str_rgb__.m from build. * scripts/plot/private/__color_str_rgb__.m: Remove unnecessary function. * scripts/plot/scatter.m: Put input validation first. Adjust indentation. * scripts/plot/scatter3.m: Put input validation first. Adjust indentation. Use htmp instead of tmp for temporary graphics handle. * scripts/plot/private/__scatter__.m: Update "markeredgecolor" in child patch objects when same property is updated in hggroup. Accept "fill" for "filled" for Matlab compatibility. Remove call to __color_str_rgb__. Don't bother saving graphics handle from __go_patch__ since it is never used. Use cellfun instead of for loop for input processing.