- Move internal.storage.Eclipse.AF3ResourceFactory -> utils.ResourceUtils.KernelResourceFactory
- Move registration of KernelResourceFactory for .af3_23 files to org.fortiss.af3.project
- Remove registration for .sfit files (should be handled in an appropriate plugin there)
refs 2309

- Instead of iteration over the entire model for each IIdLabeled element whose ID is to be checked for consistency and uniqueness, register the constraint checker for the FileProject and do each of the checks in one pass.
- Should fixes drastic performance problems introduced with last change to resolve this issue
refs 2309

- By default, EMF uses fragment-path based links to persist EReferences. While this works fine for standalone model resources, it can cause inconsistencies in case there are multiple resource models that contain cross-resource references. (I.e., if the structure of the AF3 model resource changes, the links from the external model resource can become invalid)
- The recommended way to work around this is to configure EMF to use IDs to encode EReferences.

Solution:
- Change persistence of AF3 model resources to encode references using an (extrinsic) xmi:id, that is identical to the model element's org.fortiss.tooling.kernel.model.IIdLabled.id. A dedicated XMIResource type for AF3 model resources is used (which is created by a resource factory registered for *.af3_23 files)
- The reason for not using IIdLabled.id as intrinsic ID is that the implemented solution using xmi:id is both forward and backward compatible
- At the price of losing forward compatibility, the IIdLabled.id could be changed to a derived, volatile EAttribute that simply returns the value of xmi:id
- Add EContentAdapter to sync xmi:id and IIdLabled.id
- Ensure uniqueness of IDs (that is now much more crucial) during when loading and saving as well as importing and exporting models (and print a warning to the console in case duplicates have been detected and fixed)
- As an additional safety layer, add constraint checkers to ensure uniqueness of IDs and consistency of IIdLabled.id and xmi:id

Related changes:
- Speed up loading and saving of XMI resources by setting corresponding XMLResource options
- Ensure that IDs are assigned to annotations as soon as they are instantiated
refs 2309

refs 1376

refs 694

Big refactorings to make the library mechanism more generic. Tests are green and the simulator works.
refs 694

removed conqat dependency => conqat is repackaged in org.fortiss.tooling.common and org.fortiss.tooling.common.ui

renamed ICompositionContext to IElementCompositionContext
replaced IRemovable with decomposition feature of IElementCompositor
fixed existing compositors

channel creation works on the model level, but not yet on the UI level

clean up => YELLOW

model constraint service implementation

added IConnector extensions
implemented IConnectorService
cleanup => some YELLOW

Added view icons on navigator and library.
Added editor-dependent filter for library view.

completed working undo/redo mechanism
fixed global actions update in navigator

added type system configuration selection

added editor binding extension point and service