* miscfuncs.cc (low_priority_sleep): Correct thinko which caused SetPriority to

* miscfuncs.cc (low_priority_sleep): Correct thinko which caused SetPriority to
be called unnecessarily.
* thread.cc (pthread::init_main_thread): Call new create_cancel_event function.
(pthread::precreate): Ditto.
(pthread::postcreate): Remove cancel_event creation.
(pthread::create_cancel_event): Define new function.
* thread.h (pthread::create_cancel_event): Declare new function.