Friendly error message on insufficient permissions.

Better wording.
Display error if we have no matching targets in roster.
Restore salt-ssh to working order

* Removed misleading (to me at least) messages from stderr.
* Added explicit exits to the sh shim
* Fix index error where we incorrectly detect master deploy msg.
Merge pull request #12656 from cachedout/salt-ssh-tweaking

salt-ssh tweaking