Process Engine...in progress

Today was a lot of coding, and a few headaches. ...I'll have a more complete post tomorrow.

• Finished writing process engine spec tests.
• Started building process engine.
• Discovered and resolved, after much confusion, a bug that killed active record lazy loading for the important Token object. Caused by accidentally overriding an ActiveRecord::Base method.
  
• Refactored several Token methods to use the more Rails-y hash arguments.