HBASE-12199 Make TestAtomicOperation and TestEncodedSeekers faster

Signed-off-by: Elliott Clark <eclark@apache.org>
Fix failures caused by Jacoco syncthetic methods

Signed-off-by: Andrew Purtell <apurtell@apache.org>
HBASE-11998 Document a workflow for cherry-picking a fix to a different branch
HBASE-12181 Some tests create a table and try to use it before regions get assigned (Dima Spivak)
HBASE-12206 NPE in RSRpcServices
HBASE-12200 When a Rpc server handler thread dies, throws exception (Alicia Ying Shu)
HBASE-12209 NPE in HRegionServer#getLastSequenceId