* Documentation is pretty sketchy.
* More test cases.
* AUTOLOADed get/set/add/clear methods
	- document them better
		+ can auto-generate much of this using ->format_signature 
	- ensure they can be called as get_X and get_Y where X is the microformat class/rel name, and Y is the hash key from ->data
	  which sometimes differ.
		+ make sure any such differences are clearly documented
	- when adding/setting dates, durations, etc, try to create a datatyped object
	- add get1_X methods which only get the first value in the case of plural properties
* rel=me seems broken
