Add a `restart()` command to ipcluster.py.
Add a Makefile target for restart.
Merge branch 'master' into feature/ipcluster-restart
In ipcluster.py, detects EOF for stderr, sleeps in restart.
Merge branch 'master' into feature/ipcluster-restart

Conflicts:
	distarray/tests/ipcluster.py
Merge remote-tracking branch 'origin/master'