Modify the cache_peer neighbor type when passing requests
	about specific domains to the peer.

	Usage:
		neighbor_type_domain peer-name parent|sibling domain...

	For the required peer-name parameter, use either the value of the
	cache_peer name=value parameter or, if name=value is missing, the
	cache_peer hostname parameter.

	For example:
		cache_peer foo.example.com parent 3128 3130
		neighbor_type_domain foo.example.com sibling .au .de

	The above configuration treats all requests to foo.example.com as a
	parent proxy unless the request is for a .au or .de ccTLD domain name.