Blender Git Loki

- added UI_EMBOSSR option (rounded emboss)
- added support for vector icons, from user API side is just like using
a regular icon... on icon side is defined by a function in resources.c
instead of using the blenderbuttons png file. vector icons are much
easier to add and scale properly. intent is that vector icons would
be drawn in window coordinates which lets icon developers make the
most beautiful icons, but this requires some tweaking of the interface
drawing that I am not going to do atm.
- changed BIF_draw_icon* to take coordinates of where to draw icon instead
of using passed in raster position
- switch modifier UI to using vector icons, and tweaked some position and
style stuff.
- replaced most uses of UI_EMBOSSX with UI_EMBOSS (do same thing, just there
to confuse people I guess)

After the window coordinate stuff is sorted out with vector icons
it probably makes sense to move all non-photorealistic icons in blenderbuttons
to vector form just so scaling goes better.