Revision 1001140

HBASE-3037 When new master joins running cluster does "Received report from unknown server -- telling it to STOP_REGIONSERVER..."

M src/main/java/org/apache/hadoop/hbase/master/ServerManager.java
 On regionServerReport, if we get a report from an 'unknown' regionserver,
 we used to tell it stop itself.  Now, if 'unknown' server AND
 this master did not start the cluster, its joining the cluster, then
 treat the report as a regionServerStart and register the incoming
 server rather than tell it shutdown.
M src/main/java/org/apache/hadoop/hbase/master/HMaster.java
 Pass the freshClusterStartup flag to ServerManager.
 Add more executors for opening and closing.  On cluster startup a
 master shouldn't be bottleneck clearning the server opens.
 Expose the run-balancer method so can make it available in
 ServeAdmin.
M src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java
 Minor formatting and javadoc
M src/main/java/org/apache/hadoop/hbase/ipc/HBaseRPCProtocolVersion.java
 Upped rpc version number because of new balancer addition (and because
 we didn't do it when we put in new master).
M src/main/java/org/apache/hadoop/hbase/ipc/HMasterInterface.java
 Added balance method.
M src/main/resources/hbase-default.xml
 Change how ofter we check in from every 3 seconds to every 5 seconds.