Added ceph-libvirt-dns for DNS and mira support.

Mostly just changes to ceph-libvirt-dns. Sets up an upstart job
after installing the script. Mostly effeciency changes and to make
use of pyparsing dhcp leases parser. Also Added some stuff for
Mira which does not have back access.

Signed-off-by: Sandon Van Ness <sandon@inktank.com>
Reviewed-by: Warren Usui <warren.usui@inktank.com>