HBASE-11164 Document and test rolling updates from 0.98 -> 1.0; Add note on why can't go from 0.96 to 1.0 and define what rolling upgrade is
HBASE-12322 Add Clean command to ITBLL

Signed-off-by: stack <stack@apache.org>
HBASE-11164 Document and test rolling updates from 0.98 -> 1.0
Add missing license
HBASE-12328 Need to separate JvmMetrics for Master and RegionServer (Sanghyun Yun)