Case management: wrapper API

A wrapper API that shows how to implement case mgmt concepts like:

• process instance description: (possibly) unique name for a case instance
• case roles: (possibly) defining roles for a case definition and keeping track at runtime of which users participate with the case in which role(s)
• starting a new (dynamic) case (based on an empty case definition)
• getting data from or putting data in a case file
• getting information about ad-hoc fragments in a case and triggering them
• dynamically adding tasks / processes to a case
• defining milestones in a case definition and tracking progress at runtime
• getting an overview of active tasks / processes / nodes in a case