Moved the rest of the stuff needed to run the plugin as an app to a separate app.
Fixed a bug when serializing maps

Calling 'class' on a Map does not invoke getClass() but looks for a Map
key called 'class' instead, causing a null pointer exception.
Added a unit test for inherited domain classes.
Added a unit test for JSONBuilder support.
Mentioned JSON builder support in the readme file.
Expanded the readme file.