- Add missing xpand to target for xtext 2.6.0
fix wrong product reference.
- Support for extension to contribute an IScreen. 
The ScreenFactory will read the extension registry and instantiate the
class. As it's a Composite, we need to resolve the constructor. It's the
clients responsibility to inject the IScreen with dependencies, as we
are not the correct Module owner. (Well we know about editing binding,
but not the application bindings). So the IScreen is not injected!
(Using an IExecutableInjectionFactory is not possible, as we need to
know about the constructor parameters of the IScreen).
- Add json to target.
gis module, uses the iscreen extension