delete buffers of text object when setText is called
lots of cleanup in the gl3 renderer, also cache most of ASCII chars

in the initial texture atlas.
lots more cleanup, gl3 renderer now renders filled rects
gl3 renderer now accepts the viewport size on init

the font rendering needs some work..wrt alignment both vertically and
horizontally, which both require knowing the sizes of said texts
fix texturebase off by 1 px for textbox disabled..it was starting the y

source too late (1 px too low) and it'd miss the top part. or was it the
bottom part? i forget ;)
almost done with creating an XCF (gimp file) from scratch with layers

using the default skin. Photoshop is total lock-in for everyone, and
it's silly to make a skin in such a file so that someone else has to buy
photoshop $certain-version to actually edit a skin for an open source
project. From now on, all skins will take this into consideration,
and i'm going to boot the psd file out of here, it doesn't belong.

Spent a whole day on this, here's hoping it's worth it. The theory is
that I can now create my own skin, one that is more game-like much, much
more easily.

I also fixed some issues with the coordinates in TexturedBase being off.
I'm pretty sure it wasn't my mistake that i introduced either...for at
least a few of them.