Removed PJSIP trunk overrides from setup_pjsip.py, have been backported

darcs-hash:20090706123411-58103-911db214cdaa1848974eafbd9ee3e76300f8135c
Use reentrant threading lock while Engine starts up

darcs-hash:20090706155716-58103-31eb4ebfae1aaf51cba50256aac63490552c3849