checkAndPut should integrate with MVCC, similar to how
HBASE-4583 fixed appends and increments.
Also need a test, here's one we could use (originally proposed in
The current value of some cell is 10.
I issue two concurrent requests:
A) a check and put where check value = 10, put value = 11
B) a put where put value = 50
The only result at the end of these operations that seems reasonable to me is the value of the cell being 50. If A occurred first (ACID wise), then our values go 10->11->50. If B occurred first, then our values go 10->50 (and the checkAndPut fails)