Cleaned up some more examples.

Also removed unused material Sprite parameter.

Also shortened a life cycle for particles in shapes example. Still it gets about 10 fps slower with time :/

No need to computer Beckmann texture every frame, once is enough.

Added renderer.getClearAlpha. Extended RenderPass to be able to use custom alpha clear. Fixed UVs in UTF8Loader.

Committed deployment version by mistake.

Fixed GeometryUtils.merge (normals and centroids weren't being multiplied)
Fixed misc_lookat and misc_ubiquity_test examples.

This allows, for example, better integration of additively blended materials with a regular scene.

Not to be confused with depthTest (which controls complete access to depth buffer, including reading).

Also messed up a bit with particle emitter example.

Simplified `Trident`.
Added `setX`, `setY`, `setZ` methods to `Vector3`. They're handy for oneliners (see `CylinderGeometry`).

Fixed mouse listeners on draggable cubes example, also reverted to previous aesthetic (sorry @alteredq).

I knew for loops iterating over properties were slower than numerical for loops but I didn't realize how bad it was.

Gained about 10 fps in performance test, and that was for for loop iterating over single property.

Also fixed broken examples with postprocessing.