Fixed up GL3 models and in turn primitives

-Made changes to GL3 models, so they don't crash the whole engine. Right
now they are quite a mess and adding these little fixes are not making
it any prettier, so it must be rewritten.
-By fixing models I also fixed primitives, which were segfaulting in all
manner of places, but mostly when used inside surfaces.
-Fixed GL3 fonts, so they draw with bound color and alpha. I also
changed many things to gs_scalar (including some int's) in hopes of
higher precision... ended up just making them look worse. Should really
figure out why that is.