For unix be satisfied with the 16-bit depth buffer -- revert from previous change.
For unix be satisfied with the 16-bit depth buffer -- revert from previous
change.

This is required for:
1. Some virtual machines (VirtualBox at least);
2. On windows when using Xming-mesa and doing ssh to RHEL5 machines.


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@39433 27541ba8-7e3a-0410-8455-c3a389f83636

dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root