Serialisation of OBR
OSGi Bundle Repositories are saved in a file on the Bundle cache.
OSGi related fix
Use the OSGi compatible version of I18n, fix orbisgis-dist pom in order to find bundle/ subdirestory
Merge pull request #316 from nicolas-f/feature/osgi-repo-serialisation

This PR implements the serialization of OBR. The problem with the GUI freezing discussed in #269 will be fixed in a future PR.