Reordered headers to avoid crazy boost preprocessor errors.
Removed unneeded include.
Merging code from old OSL branch.
Reverted appleseed.python includes reorder.
Merge remote-tracking branch 'upstream/master' into OSL
Use OVERRIDE, instead of override.
Made OSL an optional dependency.
Merge branch 'master' into OSL
replaced boost noncopyable by foundation's.
More OSL placeholder classes.
Made RendererServices not abstract.
More OSL placeholders.
Removed unused include.
Improved code comments.
More OSL initialization code.
Fixed Franz' comments.
Merge pull request #230 from est77/OSL

Starting OSL support.