A simple suboptimal dns server which forward requests to multiple servers according to domains.

Invocation:
	> dispatching-dns <config.yaml>

Sample Configuration:
	address: 192.168.1.1
	user: nobody
	user: nogroup
	resolver:
	  !dispatch
	    rules:
	      - ['google.com', 1]
	    targets:
	      - !cache
		cache_size: 5000
		upstreams:
		  - !service
		    address: 192.168.0.1
	      - !log
		resolver:
		  !cache
		    cache_size: 500
		    upstreams:
		      - !service
			address: 8.8.8.8
		      - !service
			address: 8.8.4.4
		log: addresses.log
