Integrated webgl with Impact

I left the font rendering blank and will get it working later, but now
all draw loops use my webgl code.
test
Draw image cell

Added separate function for drawing a cell inside of a spritesheet, as
well as some miscellaneous bug fixing. Also added extra art.
WIP: Setting up emissive rendering

Implemented Framebuffer Object for emissive but still need to implement
the actual blur
WIP: Emissive blur added to shader code

Blur still needs some work and rendering to texture doesn't seem to be
working.
Changed glLoadImage

Still working on rendering to texture, but changed glLoadImage to return
the texture object instead of requiring calling glEmptyTexture
beforehand.
import Max's code
Merge pull request #8 from nichmack/lucashaley-maxalzner

Lucashaley maxalzner