Added support for RedHat in ceph::mon

On top of adding support for the RedHat family this also adds support
for all other sysvinit based systems which rely on /etc/init.d/ceph.

This creates a [mon.${id}] section in the /etc/ceph/ceph.conf for
each mon.

Requires that public_addr gets passed in, as there is no sane default
to set for the node_addr parameter.

Change-Id: I51150c1e3316bdab20c4458e79c4aeeb15fe4bd2
Closes-Bug: #1264916
Merge branch 'bug/1264916'