Solve temporary/permanent grammar problem

- Grammars are temporary as long as somebody plays in the editor; temporary grammars need to be sandboxed for a particular user

- As soon as the grammar is saved, it is written to the filesystem as permanent grammar

- How about drafts

  • How about history/versions of grammars (something for the activity feed)

(from redmine: issue id 324, created on 2018-01-22tgradl, closed on 2018-01-22)