HBASE-9987 Remove some synchronisation points in HConnectionManager

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1543051 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9982 TestClientNoCluster should use random numbers

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1543053 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HBASE-8584-trunk-gd