fix vert attrib pointer to be set upon gui draw, so text and gui renders
unfortunately, i'm unable to come up with a solution for batching

the gui calls, it ended in a complete failure on my part, because as
soon as text is introduced into the equation, you run into depth issues.
That is, gwen itself doesn't have intimate knowledge of whether or not
a piece of text is occluded. this fix *really* *really* *must* be
further up in GWEN, and i'm betting it isn't too easy. either that or
I'm missing something entirely obvious. I suppose there are complex ways
to fix this issue of mine..but i'm not feeling it.

honestly, it's sort of a waste of time anyways, it gets 200-400 FPS and
this is without *any* optimizations whatsoever, of which there are quite
a few to be done, like limiting buffer size and texture switches.

the way to fix this problem the real way, i can only think of is by,
when you draw text somehow append a z value for it which can then be
placed against the gui elements. but they are in separate vbos, but
i think that's possible with depth testing (haven't looked into that too
much).

i really shouldn't be annoyed with it, it's better than fully immediate
mode, so by nature is loads..*loads* better than the SFML 1.6/2.0
renderer. but..patches welcome, i may revisit this area or hopefully
someone else can.