Using timer.Timer in health check, stopping it.
Implementing the lameduck code. Test to come.
More support for health check / lameduck mode.
Moving health history from health to agent.

Agent will need to take into account other stuff.
Merge branch 'master' into replication
Merge branch 'replication' of github.com:youtube/vitess into replication
queryservice: Change allowQueries

allowQueries is now simplified. It just tries to start the
query service. If it fails, it returns an error. All the
retry logic has been removed. This will allow the tablet manager
to retry based on other conditions that the query service does
not care about.
For vtocc, a failure to start the query service will cause the
program to exit.
Removing go/vt/vttablet, merging it into tabletmanager.

Still a bunch of stuff to clean up.
Merge branch 'replication' of github.com:youtube/vitess into replication
Moving HealthRecord to healthcheck.go
Cleanup up import.
Moving actor into its own library.

That way vtaction doesn't link with tabletmanager any more.
Merge branch 'ssrepl' of github.com:youtube/vitess into ssrepl
Fixing integration tests with new states.
Merge branch 'replication'