alpha.3

Changelog:

• More documentation on how to use the renderer
• New 3d asset converters: Blender export script, PNG2JSON
• Textures have alpha
• Textures accept Base64-encoded 16-bit color pixels, for reduced file size
• Fixed camera rotation in render()
• Near plane is clipped against prior to perspective division, reducing artifacts from objects located behind the camera
• An n-gon's base color now modulates its texel colors
• Sin/cos use a lookup table, for added retro vertex wobble
• Performance is somewhat lower than in alpha.2