Rewrite ROS Critical Section implementation, which was slow and broken (because it...

Rewrite ROS Critical Section implementation, which was slow and broken (because it always created an event, which is the slow path). Note that coincidentally, Gunnar also fixed this code and committed a patch this morning, taken from WINE. This code is also based on WINE, but adds more features which WINE does not support/need yet (regarding Debug CS). Hence, this code was a re-write of the original ROS code, not of Gunnar's, and we've both discussed the accidental conflict.

svn path=/trunk/; revision=12766