Version 0.22:
	* QPID-4466: qpid::messaging::Duration now supports multiplication
	* QPID-4416: Messages with embedded nulls won't break on getContentPtr
	* QPID-4505: Provides unit tests for Address, Duration and Message
	* QPID-4504: Broke up the Per classes into separate source modules
	* QPID-4580: Added perldoc markup to each source module