Fixes #6543 - updt index on cp event bz1115602

This listens for entitlement events from candlepin and updates the specific
pool index instead of pulling all the subscription information each time
the user accesses the subscriptions page.

New gem dependency added: qpid_messaging
gem has dependency qpid-cpp-client-devel and qpid-cpp-client
rpm packages.
@ehelms, @GregSutcliffe  is there away to add the gem dependency only when the app is in development or production but not test/jenkins env? That way we don't have to limit to jenkins slaves?