Fixes to user module for better error handling
Fixes to user module for better error handling

The user module now returns the output, both stdout and stderr, from
useradd, usermod, and userdel.  This should help debug cases why one of
those commands fail.  In addition, the user module will now call
fail_json() when the attempted command failed so as to properly
communicate a failure in a playbook.

thaim/ansible,thaim/ansible