Bumped to v426
Bumped Stage3D's required Flash version to 11.7 since Adobe de-optimized PixelBender with Flash 11.7
Merge pull request #510 from LLK/bump_stage3d_req

Bumped Stage3D's required Flash version to 11.7 since Adobe de-optimized...
Moved 3d_render_src contents into src

To simplify building and debugging the 3D rendering code, I moved it
into the main src/ directory. This breaks the AIR 2.6 build, but an
upcoming change will fix that.
Reformatted code
Wrapped 3d code with conditional compilation flag

The 'SCRATCH::allow3d' flag now controls 3D-related code.
Fixed Ant build WRT SCRATCH::allow3d compile flag