Fix T41839, OpenCL error.

Also some style fixes, we don't do the "put as much as possible in 1 line" contest.
Cycles: tentative fix get rid of os-specific issue in struct ShaderClosure ( aligment issues due order )
Utility script to create release archive

- only include files known to git.
- includes all submodules.
- version extracted from BKE_blender.h for naming.
- MD5 checksum generated.
- 'make tbz' convenience target.

Script by Dan McGrath with own minor edits.