* Make branch deletion URL more like GitHub's, fixes#1397
* Add PR branch deletion integration test
* Do not allow deleting protected branch
* Change http error code to 403 if user has no write rights to repository
* Add check to not panic if forked repository has alrady been deleted
* Do not allow commiting to protected branch from online editor
* Add editor integration tests for adding new file and not allowing to add new file to protected branch
