Handle messages posted to the TriggerInstance work Q.
Proper handling for a TriggerInstance in the RulesEngine.
Mirgate core sensors to use new sensor interface
Update launchdev.sh to start rulesengine.
Update st2ctl to start rules_engine
Update packaging.
Startup fixes

- Fix missing import
- Add execute permission on script
Adding logging.conf for rulesengine.
Allow poll_interval to be None and add support for passive sensor mode to the
SensorWrapper.
Add new sensor class hierarchy which provides a better abstraction and
delegates responsibilities better.
Remove unused imports.
Update sensor wrapper so it works with the new class hierarchy.
Intercept original exceptions and throw more useful ones.
Merge branch 'master' into sensors_process_sandboxing

Conflicts:
	tools/st2ctl
Update Python runner to parse action result and store it in a dictionary
under the key "result".

This way result is not only accessible through "stdout" key anymore and it's
not mixed with other stdout output.
Fix a typo.
Update affected python action runner tests.
queue watcher -> queue consumer.
Add "queue producer" debug utility which allows user to send test messages to a
particular exchange.
Fix a typo.