Added users cookbook
Updated references for account, backup2l, hosts, libvirt, mysql, nginx, ntp and php
Merge branch 'master' of github.com:tboerger/cookbooks

* 'master' of github.com:tboerger/cookbooks:
  Updated ntp reference
  Updated ntp reference
  Updated account reference
  Updated users reference
  Fixed typo
  Updated users reference
  Updated libvirt reference
  Removed outdated directories, updated references and added users cookbook