Ok to remove and change return types on methods in a public/unstable testing utility class in hbase-2.0.0?

[Stack]

I am looking at changes to a HBaseTestingUtility base class over in the
nice cleanup issue HBASE-13893.  HTU is a pretty popular testing tool.

I'm thinking that is is not OK removing methods and changing param and
return types even though its across a major version (and even though it
marked unstable) because we should spare the user pain where we can.

On other hand, we are purging HTable references, old crud, the preservation
of which is useless and will make for a mountain of work.

Opinions?

St.Ack