Blender Git Loki

Redoing the blur filters for composit;

http://www.blender.org/bf/filters/

I found out current blur actually doesn't do gauss, but more did regular
quadratic. Now you can choose common filter types, but more specifically;

- set gamma on, to emphasize bright parts in blur more than darker parts
- use the bokeh option for (current circlular only) blur based on true
area filters (meaning, for each pixel it samples the entire surrounding).
This enables more effects, but is also much slower. Have to check on
optimization for this still... use with care!