Make the qpid create/delete user use templates.

Instead of automatically appending on the
user name to the command to be executed
just use a template (which matches how
we are doing this elsewhere) and untemplatize
the command to be ran instead.

Change-Id: I63008f27874f22bc9ce6d90eebe6fc7fc4cd9237
Merge "Make the qpid create/delete user use templates."