This is how compressed textures are supposed to be used:

DXT1 - RGB - opaque textures
DXT3 - RGBA - transparent textures with sharp alpha transitions
DXT5 - RGBA - transparent textures with full alpha range

This is unlikely to work properly in the short term though.

See #2358

Required some tweaking to CanvasRenderer material logic.

Not sure how they lost it.

Thanks to @toji for blog post and DDS utilities.

Fixes #2348

TODO: example textures for alpha formats (DXT3, DXT5).

Conflicts:
	build/three.js
	build/three.min.js

Giving a chance to mobile :)

See #2349

Particles are rendered using drawArrays, so there is no need for indices or offsets.

Particle sorting not implemented for BufferGeometry, will need to check if this is possible to do efficiently.

Normal maps store the perturbation of the surface normal (vector field), as opposed to bump maps, which are height fields (scalar field).

See #2352

Work-in-progress, don't merge yet.