We export the core functionality of the model allowing
other plugins to use it.

The general functionality was already there, but I had
to rename the macro to avoid name clashes.

Also I renamed the .pri file to avoid confusion.

Change-Id: I88203ce9dbfddc8d734e5e232ff71bc0e244e5b8
Reviewed-by: Marco Bubke <marco.bubke@digia.com>