* Fixes vertices with bad coloring. Now vertices draw with depth write so
they occlude the underlying face geom overlay, avoiding double drawing the
vertex.
* Decrease the z_offset of edges so they don't poke too much through
geometry. Also delete this offset in ortho view.
* Add zoffset to active and selected vertices so they always draw on top
if they overlap a non selected vertex.
* Fix alpha of edge_fix in vertex selection mode
23c3124b56