Move common handlers in handler.py module.
Add InitializationHandler, applied on the master connection while retreiving
the partition table and node list.
Replace a call to (inexistant) method handleUnexpectedPacket with a raise of
UnexpectedPacketError exception.


git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@788 71dcc9de-d417-0410-9af5-da40c76e7ee4