COWDB2 release 2-0.2

In this release we have made a big change to the object model. We now pass references to the Application object place of references to the aggregate element, making the object model largely transparent. So when using the API, you pass application objects as arguments and the returned values can simply be cast appropriately. Internally we now also have strong typing, as everything is no longer simply a CElement.

One consequence of this is that for every element need an application object, so we've had to add a lot of Application classes for the various element roles used by the framework.

There has also been a change to the implementation of transactions. They are now simply facods, carrying a reference to their associated element. Facods are strictly transient and are not aggregated into the element.