remove restapi, fixes #2798

RELEASE-NOTES.md

app/controllers/activityfeed.php

app/controllers/admin/api.php

app/controllers/api/authorizations.php

app/controllers/api/oauth.php

app/controllers/resources/ajax.php

app/routes/Activity.php

app/routes/Blubber.php

app/routes/Clipboard.php

app/routes/Contacts.php

app/routes/Course.php

app/routes/Discovery.php

app/routes/Events.php

app/routes/Feedback.php

app/routes/FileSystem.php

app/routes/Forum.php

app/routes/Messages.php

app/routes/News.php

app/routes/ResourceBooking.php

app/routes/ResourceCategories.php