Cleaning up the binlog_server response.

Also moving a few definitions into proto.
Use full keyrange for monitoring, not just end.
blp_recovery is no more, it is blp_checkpoint.
Renaming RestoreFromMultiSnapshot to Multirestore.
Merge branch 'master' into resharding

Conflicts:
	go/cmd/mysqlctl/mysqlctl.go
	go/vt/mysqlctl/binlog_player.go
	go/vt/mysqlctl/binlog_server.go
	go/vt/wrangler/split.go