fixes Bug 928519 - added missing references to the quit check method

The PolyCrashStore class was failing to propagate the 'quit_check' call back function to all the subordinate crash storage instances.  This hampers the ability for the configman apps to react quickly when given a SIGTERM.  The RabbitMQ new crash source also failed to use the quit_check method it was given.

Please note, this is _not_ the PR that introduces killing sub-processes.  This is just a first step to getting to that goal.