Clean up scheduling algorithms to pass unit tests and hopefully eliminate reported deadlocks. Still needs work, but should be better than before.

[SVN r23849]

libs/thread

@@ -1 +1 @@
-Subproject commit 59fba2bff6bbf89e4fbedfe67f6b7f8571dfbc63
+Subproject commit d29dae72de157ce45dc43d4946fccf7cd6ac27cf