Basic state machinery

TODO:
* Logging
* Tease out transition actions vs enterstate actions, pre and post-signal hooks
* Design UI flow interface (library/WikiPages.php)
* Machine ID and Workflow Instance ID; address signal to known job
* Suspend machine & persist state
* Provide full examples, or even better, verbose integration tests
* Remote API and token
* ContentHandler for the Workflow: namespace
	syntax validation