rewrite mesh to only need 17 indices per cube, and 7 values per vertex using TRIANGLE_STRIP

color data is now packed into an int, shaders will need to unpack via unpackUNorm4x8
layout of buffer data is also changed, vertex coords, then normals, then color data.
no longer expose indicies/vertex additions, simply tell the mesh where to put a cube.

Signed-off-by: Nick Minkler <sleaker@gmail.com>