Replace wget with curl on OSX

darcs-hash:20090219203755-58252-66fd7ba142881ecde2b939781a10218f831c90ef
Made Invitation more resilient when used after PJSIPUA has been dealloced

darcs-hash:20090220102002-58103-e286ddbeb156c3fd52ae30ecf6d22986f83997de