Improved edge subdivide. The last tool panel
is a bit clearer, with a "quad/tri" checkbox
(that, in addition to turning on the old
singe-edge-triangluation feature also
automatically switches cornervert to Inner Vert
if it is Straight, to avoid producing ngons).
I also rewrote fractal to be more likes its name, and
removed the "smoothness" parameter (which never
worked, anyway, even in trunk). Also removed the
grid fill paramter, it wasn't all that useful.
client-defined data. Made edge subdivide use it.
Also removed the float and int slot buffer types, as per
discussion with Briggs, until such a time as we see
a use for them.
