add EngineTracer to sipsimple.logstate - debugging tool for dumping all SCEngine's events

darcs-hash:20090211124731-b2873-8a08d1aae343d776de7b6ad7c7024fbf2aa77e09
add sipsimple.green.notification - helpers to simplify use of application.notification with eventlet

darcs-hash:20090211124934-b2873-b07e3800995862da53d83ffef367fd4ff51258a2