Blender Git Loki

Patch #4970 (brecht)

Added: Scale node in Compositor.

- Only works for RGBA buffers now
- I have added an option "Relative" or "Absolute" scale. So you can also
define actual pixels for scale. Values for scale are reset when you
switch, to prevent too weird situations.
- Scaling wasn't foreseen to work with the preview-panel in UV window, this
preview cropping only happens for Image and RenderResult nodes... actually
should be done for the scale too. I wait with t hat though... this preview
method isn't very advanced yet.
- The pass_on_compbuf() here crashed in tests with preview panel, that's
weak code... I have to recode that. For time being I use the
dupalloc_compbuf to have it stable.