HBCK options to disable master maintenance threads

[Stephen Jiang]

      } else if (cmd.equals("-disableBalancer")) {

        setDisableBalancer();

      }  else if (cmd.equals("-disableSplitAndMerge")) {

        setDisableSplitAndMerge();

In HBCK, we will either use the options to disable master maintenance work
(see above) or the master maintenance are disabled during repair.

I think we should always disable master maintenance work during online
HBCK, because balancer moving regions around during online check; or
split/merge regions during online check would have unexpected side effect.

How do you think?

Thanks
Stephen

Also, I think we have too many options.  We really should reduce options in
hbck so that it is more user friendly (eg. currently implementation of
-fixHdfsOverlaps would almost 100% create hole, it does not make sense to
run it alone, it should always run with -fixHdfsHoles option; and very
likely with -fixMeta option)