HBASE-12337 Import tool fails with NullPointerException if clusterIds is not initialized
HBASE-12449 Use the max timestamp of current or old cell's timestamp in HRegion.append()
HBASE-12411 Optionally enable p-reads and private readers for compactions.
HBASE-12517 Ensure HConstants members are final.

Signed-off-by: stack <stack@apache.org>

Conflicts:
	hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java

Conflicts:
	hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java
HBASE-12513 Graceful stop script does not restore the balancer state

Signed-off-by: stack <stack@apache.org>
HBASE-12496 A blockedRequestsCount metric (Yi Deng)
HBASE-12277 Refactor bulkLoad methods in AccessController to its own interface (Madhan Neethiraj)
HBASE-12529 Use ThreadLocalRandom for RandomQueueBalancer
HBASE-11992 Backport HBASE-11367 (Pluggable replication endpoint) to 0.98 (Ramkrishna S. Vasudevan)
Update POM version to 0.98.9-HBASE-11992-SNAPSHOT