Improve check which sees if Supervisor is running

Instead of just checking if the socket file exists, we should also check if the PID written to the PID file exists.
basic auth for couchdb integration
remove unneeded changes
Merge branch 'master' into couch_basic_auth
Merge pull request #931 from DataDog/couch_basic_auth

basic auth for couchdb integration
Merge pull request #901 from Tenzer/improve-supervisor-running-check

Improve check which sees if Supervisor is running
Fix was actually in Docker 11
Merge with master