Purge hokey hbase Service implementation; use (internal) Guava Service instead

Purge useless hbase Service class. Having it around only confuses. Purge it here because we thought it might be of use fixing parent issue but it only confused the issue. And now it is safe to use Guava Service with its nice supporting facility (including ServiceManager for running many at a time).

Introduces "hbase.master.wait.on.service.seconds", a new config. for how long Master should wait on a Service to start or stop.