Bundletree-core integration

Start using `bundletree` as unique module scanning OSGi bundles and being aware of OSGi un Java source code. It implies:

* Remove OSGi dependencies in all bundles except `bundletree` one.
* Remove old `Activator` from `core` bundle.
* Manage instantiation using IoC using OSGi blueprint in `bundletree` and `core` bundles.
* Adapt `BindingManagement` class to use `BundleGuard` provided by `bundletree` module.
* Adapt integration and unit tests to these changes.
* Use dummy BundleGuard for unit tests in `core` bundle.