HBASE-12118 Explain how to grant permission to a namespace in grant command usage
HBASE-12098 User granted namespace table create permissions can't create a table (Srikanth Srungarapu)
HBASE-12099 TestScannerModel fails if using jackson 1.9.13 (Esteban Gutierrez)
HBASE-12115 Fix TableInputFormatBase.reverseDNS for ipv6 addresses

Summary: Hadoop's DNS.reverDns function cannot handle Inet6Address properly and throws Runtime Exceptions.

Test Plan: Added Unit test to test the particular case.

Differential Revision: https://reviews.facebook.net/D24225

Signed-off-by: Elliott Clark <eclark@apache.org>