Particles cleanup, optimizations and some small new stuff.

Particles cleanup, optimizations and some small new stuff.

New stuff
- Bending springs for hair dynamics.

Code cleanup & optimization
- Disabled reactor particles temporarily for cleanup, it's a clumsy system that will be replaced with something better.
- Removed child seams, something better will come here too :)
- Normal particle drawing data is now saved between redraws if the particles don't move between redraws.
	* For example rotating the 3d view is now realtime even with 1M particles.
- Many random values for particles now come from a lookup table making things much faster.
- Most accessed small point cache functions are now much faster as macros.
- Lot's of general code cleanup.
- Nothing big should have changed so if something doesn't work like it used to it's probably just a typo somewhere :)