HBASE-9792 Region states should update last assignments when a region is opened

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1539731 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9909 TestHFilePerformance should not be a unit test, but a tool

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.96@1539767 13f79535-47bb-0310-9956-ffa450edef68