Added alphaTest parameter to base Material plus corresponding shader chunk in standard materials implementation.

This is for having on/off transparency without sorting using threshold value in alpha channel of diffuse texture.

By default it's switched off (alphaTest = 0).

AlphaTest is not yet handled in shadow maps. This would require passing of diffuse texture to depth material in shadow map render step (and more permutations of depth material).

Added Matrix4 type to uniforms. Fixed Texture cloning. Fixed uniforms cloning for Vector2, Vector4 and arrays.

Gah, these things are pain to debug - "undefined" value in uniforms can lead to very weird behaviors.

Updated misc_sound example with same functionality.

Reverted to previous WebGLRenderer.setTexture code. Now that Chrome 12 is out, it should be working?
Commented out troublesome object-behind-camera check in Ray.js

Added handling of removal of particle systems, ribbons, lines, shadow volumes, marching cubes.

Fixed bug with partial mesh removal.

Having these "undefined" for non-mesh objects was causing unnecessary GL state setting when having scenes with mixed content (and coercing "undefined" to boolean turned out to be similarly costly as state setting).