Resync utils, ceph, add support for keystone auth
Updates to docs for keystone integration
Improve host ip resolution - fixes issues with maas managed DNS
Allow DNS problems to bubble up and break hooks as things are broken if this
is the case.
Add support for Ceph Bobtail LTS release

- Add support for keystone based authentication (use keystone charm).
- Misc other updates including new cephx options.

Fixes

- Improve hostname -> ip address resolution
- Disable 100-continue processing as requires a fork of mod_fastcgi
- Resync utils.py, ceph.py across ceph charms.