Move more bind config into domtool, remove hardcoded /var/domtool references

Move more bind config into domtool, remove hardcoded /var/domtool references

dns_master_node and dns_slave_nodes do not need to be defined in SML,
and were removed.

Instead of checking Config.Bind.masterNode and skipping generating a
zone file on bind slaves, don't generate the incorrect soa.conf at
all (same effect, but the correct way).