WIP: Make rabbitmq-server keep state in /mnt/state

Note that it was not using an o-r-c script to be restarted because it
didn't have any config files that might change. We've added one to move
the state now, so we need to restart it.

WIP as this is untested entirely.

Change-Id: I8e12b7e84a355f50b55413a391a4b1c58428af82
Merge "WIP: Make rabbitmq-server keep state in /mnt/state"