HBASE-12177 TestIPv6NIOServerSocketChannel hangs consistently on Java 8

Disable hanging tests on Java 8 for investigation
HBASE-12011 Add namespace column during display of user tables (Srikanth Srungarapu)
Revert "HBASE-12177 TestIPv6NIOServerSocketChannel hangs consistently on Java 8"

This reverts commit 7f8a86441ed9177498a7e73b2815055fd5271b54.

Further investigation indicates this is an OS or JVM issue on the
test host
HBASE-11890 HBase REST Client is hard coded to http protocol
HBASE-12104 Some optimization and bugfix for HTableMultiplexer (Yi Deng)
HBASE-12184 ServerShutdownHandler throws NPE
HBASE-11815 - Flush and compaction could just close the tmp writer if
there is an exception
HBASE-12106 Move test annotations to test artifact (Enis Soztutar)
HBASE-12039 Lower log level for TableNotFoundException log message when throwing (stack)
Update POM and CHANGES.txt for 0.98.7
Exclude dev-support/hbase_docker/README.md from RAT
Amend HBASE-12106 Move test annotations to test artifact (Enis Soztutar)

Add hbase-annotations as a test-jar dependency in hbase-testing-util
Merge remote-tracking branch 'remotes/origin/0.98' into 0.98