implementation of the federated share provider

.gitignore

apps/federatedfilesharing/appinfo/app.php

apps/federatedfilesharing/appinfo/info.xml

apps/federatedfilesharing/lib/addresshandler.php

apps/federatedfilesharing/lib/federatedshareprovider.php

apps/federatedfilesharing/lib/notifications.php

apps/federatedfilesharing/lib/tokenhandler.php

apps/federatedfilesharing/tests/lib/addressHandlerTest.php

apps/federatedfilesharing/tests/lib/tokenHandlerTest.php

core/shipped.json

tests/enable_all.php