HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [1/8]

HBASE-11059 ZK-less region assignment (Jimmy Xiang)
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [2/8]

HBASE-11687 No need to abort on postOpenDeployTasks exception if region opening is cancelled (Jimmy Xiang)
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [3/8]

HBASE-11725 Backport failover checking change to 1.0 (Jimmy Xiang)
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [4/8]

HBASE-11659 Region state RPC call is not idempotent (Virag Kothari)
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [5/8]

HBASE-11531 RegionStates for regions under region-in-transition znode are not updated on startup (Jimmy Xiang)
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [6/8]

HBASE-11814 TestAssignmentManager.testCloseFailed and testOpenCloseRacing is flaky (Virag Kothari)
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [7/8]

HBASE-11615 TestZKLessAMOnCluster.testForceAssignWhileClosing failed on Jenkins (Jimmy Xiang)
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [8/8]

HBASE-11814 TestAssignmentManager.testCloseFailed() and testOpenCloseRacing() is flaky (Virag Kothari)
Revert "HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [8/8]"

This reverts commit d487526888223a94bf37cc446cbf916fcd4a2535.
HBASE-11546 Backport ZK-less region assignment to 0.98 (Virag Kothari) [8/8]

HBASE-11610 Enhance remote meta updates (Virag Kothari)
HBASE-9746 Addendum.