explicitly do not run chrooted (bnc#787344)
Expose nameservers chef attribute to crowbar proposals

Allows to add additional nameserver entries in /etc/resolv.conf already in a
'dns' proposal.
Fix wrong /etc/bind/named.conf template

No need to add empty "forwarders { };" option.
Provide "allow_transfer" proposal / chef attribute

To configure zone transfer in /etc/bind/named.conf