Check if local services are up before starting them

- Ran into this issue when using a local master/slave.  If
the master and slave were already up, using the build command
would wipe out the clusterrunner_slave.log, try to start the
slave service again, and log some ugly exceptions.

- Now we check if the master is up first, and abandon starting
local services if so.
There's a check in run_master() which aborts if the master is already running, so that part was ok.  But yeah, it would try to start the same slave, and rotate the slave.log