UV mapping for Extrude Geometry - now ExtrudeGeometry takes in 2 additional parameters, material for front/back faces, extrudeMaterial for extrusion and beveled faces

Add arc parameter to TorusGeometry, so it can be used to build half-tori and quarter-tori (e.g. for 90-degree pipe bends).

Updated Tween.js (thx @jeromeetienne)

This kinda works in Chrome, though not in Firefox.

I give up on canvas renderer in these two examples in FF, it's anyways extremely slow with nontrivial textured models.

Slightly modified ro.me buffalo test - using alpha test instead of alpha transparency to get rid of artefacts, also increased number of buffaloes to 375.