[DISCUSS] Road to HBase 2.0.0

[Josh Elser]

Since 4.12.0 is out and we have the concurrent discussions about the 
0.98, 1.1, and 1.2 HBase branches, do folks have a vision of how we get 
to HBase 2.0.0?

The lack of chatter is pretty obvious that the Calcite work (the 
previous impetus for Phoenix 5) has slowed. Once we get to an HBase 
2.0.0-alpha4, coprocessor API should stabilize and give us a point 
against which we can start Phoenix work.

Should a release of Phoenix that supports HBase 2.0 be worthy of the 
Phoenix 5.0 label, or should we stick to the 4.x numbering? Given the 
breaking changes going into HBase 2.0 and James' previous -1 to 
shim-layers for 0.98, do we see the same for an HBase 2.0 branch or is 
HBase 1.x/2.x a different beast? I can see pros/cons for both sides.

- Josh