Fixed bugs where the _disable_threads lock could fail to hold the threads if there are threads dependent on uid or similar running when the _disable_threads lock is requested. This bug could cause numerous "Cannot wait for mutexes/conditions when threads are disabled" backtraces when _disable_threads is used (e.g. through the Privs class in Roxen). Cf [bug 1173 (#1173)]. Rev: src/modules/Java/jvm.c:1.36 Rev: src/signal_handler.c:1.193 Rev: src/threads.c:1.159 Rev: src/threads.h:1.113