The editor should (auto) save drafts while editing a page.
Notes:
The draft is removed as soon as the page has been comitted.
The draft will not be saved in the repository, because this would need a proper commit (and fill up the change log)
When a user navigates to a page where a current draft (by the current user) exists, this is displayed with the option to continue editing or to discard the draft. In case updates bu other users happend the page in the meantime, a warning will be displayed.
The editor should (auto) save drafts while editing a page.
Notes:
As discussed in #60.