Added options possibilities
allow user to control allow-recursion on the global level
support FreeBSD
Look up out-of-scope variables from templates
Allow to configure listen-on-v6
In some internal networks ipv6 might not be working as expected soallow to turn it off.
Use @var for puppet 3.2 compatibility
Parametrize the classAlso add forwarders as a parameter
Forked from zleslie's dns module, reworked for theforeman