Adjust to latest go-etcd recursive get/watch/delete API

go-etcd changed the API again, they removed GetAll/WatchAll and now Get/Watch/Delete have a 'recursive' bool parameter.
Merge pull request #19 from mmikulicic/patch-1

Adjust to latest go-etcd recursive get/watch/delete API
Fix go-etcd calls in etcd backend test
Use our fork of go-etcd
fixing merge conflict
delete function signature change
switched back to channel-based Watch mechanism on ServiceSet with ability to get current state updates. Renamed client.GetServices() to Services() and QueryServices() to ServiceSet(). made sure client.Services() calls Close() on service set.