Experimental code of import wizard's port definition pages.

Port definition pages for Event-B and FMU components, modified from the
code of GMF simple tooling wizard. Unfinished.
EventBComponent's order of supertypes switched back.

Order of the classifiers used as supertypes for EventBComponent is
switched back to AbstractExtension (first), Component (second) to fix
code generation problems and persistence problems with extended
Machines.

Additionally, the default extension id for EventBComponent is set in a
constructor to a default constant (temporary solution for resetting the
id constant defined in the AbstractExtension superclass).
Added components UI plug-in with image registry.
FMI utilities class for FMI to metamodel type conversion.
FMU definition page.

* Added code by Matthias for FMU variable definitions on component
import.
* The page is refactored and integrated into component import wizard.
* Empty page for Event-B port definition added and requires
implementation.
* Additional bug fixes and code enhancements.