Update README to reflect spec changes and unsupported features
Update README to reflect spec changes and unsupported features

Acidburn0zzz/getdns,smogali/getdns,glenwiley/getdns,glenwiley/getdns,shane-kerr/getdns,Acidburn0zzz/getdns,glenwiley/getdns,smogali/getdns,dkg/getdns,huitema/getdns,dkg/getdns,Acidburn0zzz/getdns,huitema/getdns,shane-kerr/getdns,dkg/getdns,Acidburn0zzz/getdns,glenwiley/getdns,shane-kerr/getdns,dkg/getdns,huitema/getdns,shane-kerr/getdns,smogali/getdns,huitema/getdns,smogali/getdns