Blender Git Loki

Improvements to Blenders color balance (lift/gamma/gain).
Fairly closely match some mac application colin has called 'Looks', to give better results.
- lift is now applied non linear (was being added to the color)
- change the color wheel to preserve the luminance of the gamma and gain values, this stops the color from being set too dark (option for the color wheel template).
- sub-pixel precission for the color wheel since the white area at the center can make a lot of difference with a very small change.

This change will make existing node and sequencer setups lift render slighly differently however discussed this with Ton and he's ok with it.