went to a more Go-style representation of host/port for Register, Unregister, Heartbeat. works with latest server that will accept port-only Addr values (ie ':8000'). RegisterWithHost is just a matter of specifying the host/ip in the Addr value. Register now accepts no attribute values and instead wraps RegisterWithAttributes that will let you specify attributes
Merge pull request #2 from flynn/minor-api-rev

went to a more Go-style representation of host/port for Register, ...