Blender Git Loki

Todo item:

Compositor: Texture Node now behaves like an image.
- Image always in render output size
- Buffer outputs RGBA and Value both supported
- Works for filter and blur and scaling too.
- Mixing 2 textures works

Implementation note:
The texture node was meant to be 'procedural', not a buffer
but a color-sample method. Unfortunately the node editor
didn't support this well, blur/filter/scale ignored it too.

For now, its better to drop this procedural concept, then
things work at least as expected. :)