Salt module version check

[smithfarm]

From @Martin-Weiss

". . . add a function to ceph-salt that can detect version differences of modules.. (ceph salt brings new modules so it should also be able to verify the module version on the salt-master and on the salt-clients I hope..)"

Thus, when the ceph-salt-formula RPM is updated and the user forgets to run "saltutil.sync_all", ceph-salt would detect a version number mismatch and refuse to continue. Instead, it would instruct the user to run "saltutil.sync_all" and try again.

IMO this would be a great thing to have.