Remove out of date comment.
Fix packs management commands to use correct base virtualenvs path.
Return a result from the setup_virtualenv action.
Fix entry points.
Fix packs.unload action.

Python actions now run in a separate process which mean we need to establish
the database connection inside the action.
Update packs.unload action to also delete SensorType, TriggerType and Trigger
db objects for the pack which is being removed.
Fix the function - should use cfg.CONF.content.packs_base_path instead.

Also update affected tests.
Install oslo.config inside every pack virtualenv.
Fix packs.setup_virtualenv action so it works correctly when this action
is running in a separate subprocess.
Log the command used to run the sensor process.
Fix a typo.
Move variable in a constant module.
Also don't allow "packs" pack to be uninstalled.
Don't allow user to unload / unregister system packs.
Use consistent function order.
Don't default required arguments to None.
Register script can now also register sensors.
Dispatcher -> SensorService.
"packs" pack ships with the default installations so we can use a constant from
st2common for the base pack requirements.
WIP: Move webhooks to API