API updated + preliminary support for timers.
Added comparison function to wf_date.
Stubbed support for more actions, including timers.
Added workflow start entrypoint. Bugfix: Fixed nyi to use handle_failure. Refactor: wf_state is now a record.
wf_tq: persistent queues lib added. wf.hrl: record declarations. wf.schema: schematool declarations.
Updated schema target to use schematool. (Requires user to clone this tool though.)