Split old reactor configuration into two new configuration section -
"sensorcontainer" and "rulesengine". This way sensor container and rules
engine options are not mixed together (it used to make sense when
RulesEngine was running inside the sensor container, but that's not the case
anymore).

Also update affected entry points and config files.
Update launchdev script - start the st2api service first and register
all the content as soon as the API is started.

With the new approach, sensor_container queries sensors from the DB which means
we need to register sensors before we can run the sensor_container service.