Policy reserved domains

According to RFC6761 query to localhost domain should generate immediate response with loopback ip address.

Added test. and invalid. to special domain list

Also allows to disable specific deny rules from reserved domain list on zone-by-zone basis as it should be according to RFC6303 sec.3. Disable can be done by policy rule PASS. Also any FORWARD rule for such zone will be evaluated before DENY that query.

#205 (closed) implement reserved domains properly.