BUG-7033: Implement batchHint in ShardDataTree
Modified ShardDataTree to properly compute the batchHint flag
that is passed to persistData. Basically if the next transaction
in the pendingCommits queue is in the COMMIT_PENDING state then
batchHint is set to true. After the call to persistData the next
transaction in the pendingCommits queue is processed which, if
COMMIT_PENDING, will be batched for replication with the previous
transaction.
Change-Id: I938e98391c69d617901e7e179c93e066667c017d
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>