Attempt at passing UV texture coordinates from attributes, instead of uniforms
Revert "Attempt at passing UV texture coordinates from attributes, instead of uniforms"

This reverts commit ce2c76c67aaf52a49cdc0c6cecc83cc752f7f606.
Restore three.js passing UV coords, though unused (commented out - texCoord=vUv stretches)
Set tileCoord from passed vUv coordinate (topmost only)

Gets close to proper material texturing, but not quite. Some block
faces render as expected but others have the wrong texture. Still,
closest I've gotten so far yet with greedy meshing + atlas uv + vjs..
Flip texture Y (aka V, aka T) in JS instead of GLSL
Remove UV coord rotation - side textures are now correct, but need rotation
Add rotation in GLSL per side. Textures finally correct!

At last, texture atlasing with greedy meshing. In summary,
used the UV coordinates from three.js (may be a better
way to do this?) as the starting tile texture offsets,
then repeated with tile UVs from fract() of pos . n. Works
but this custom shader is very basic at the moment.

Ref https://github.com/deathcap/voxpopuli/issues/19