Deleted unused prefabs and cleaned up used ones.

Fixed transform scaling and position on several prefabs.
Scene View cleanup in BuildScene. Modified related prefabs.
Remove sections from scene (they're all prefabs).
Removed hard coded Y-Offset on pickup and block spawns. Removed loads.

Added Y-offset into all placeholder positions in section prefabs instead
of hard coding it in script. Put loads of block prefabs on Awake. This
also moved a string lookup out of update.
Created Red, Green, and Blue Crsytal prefab to minimize material changing.

Section now loads all three crystal colors and knows which to spawn, which
keeps us from having to assign color.
Removed commented out code to do Power stomping.
Did a texture compression pass and set project settings for web player.
Merge branch 'performance_improvements'