storing celery state in /opt/celery, to preserve tasks across runs
killing rabbitmq before trying to restart it
not erasing rabbitmq data when starting as slave
Merge remote-tracking branch 'org/master' into preserve-celery-state-across-reboots
correctly restoring rabbitmq data stored on ebs volumes
added comment explaining why we use rabbitmq on EBS
Merge remote-tracking branch 'org/master' into preserve-celery-state-across-reboots
Merge pull request #818 from shatterednirvana/preserve-celery-state-across-reboots

Persist Task Queue tasks to EBS/PD
Catch generic exceptions and do not use -9 to bring down appservers
Merge branch 'master' of https://github.com/AppScale/appscale into java-composites
Merge branch 'stability_fixes' of https://github.com/nlake44/appscale into java-composites