Major update to release process documentation:

Major update to release process documentation:
- Provide overview of OpenOCD versioning schema.
- Outline responsibilities and authority of the release manager.
- Explain the need for flexibility in the release schedule.
- Add and refine the release process steps.
- Include tutorials for using new release script.
- Many more improvements, too numerous to list.

git-svn-id: svn://svn.berlios.de/openocd/trunk@2462 b42882b7-edfa-0310-969c-e2dbd0fdcd60