Revision 658465

HBASE-504 Allow HMsg's carry a payload: e.g. exception that happened
over on the remote side.

M  src/test/org/apache/hadoop/hbase/TestSerialization.java
    Add test that HMsg with region and message serializes.
M  src/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
    HMsg types have been enumified.  Also use some of the new
    static messages.  On split and close because of error,
    add message to the HMsg we pass back to the master.
M  src/java/org/apache/hadoop/hbase/HServerInfo.java
    (compareTo): Added.
M  src/java/org/apache/hadoop/hbase/HRegionInfo.java
    Allow null in compareTo.
M src/java/org/apache/hadoop/hbase/master/ServerManager.java
    Use the new HMsg.isType figuring message type.
    Redo message logging.  Use convenience HMsg statics.
M  src/java/org/apache/hadoop/hbase/master/RegionManager.java
    Pass back overloaded message if region shutdown because of balancing.
M  src/java/org/apache/hadoop/hbase/HServerAddress.java
    Make it so that two addresses equate even if one has hostname
    and the other IP.
M  src/java/org/apache/hadoop/hbase/ipc/HMasterRegionInterface.java
    Up the protocol version for regionserver reporting master messages.
M  src/java/org/apache/hadoop/hbase/HMsg.java
    Enumify the messge types.
    Define a few static HMsgs for convenience.
    Allow optional message. Improved toString.
    (isType, equals, hashCode): Added.