Problem statement

When a user attempts to edit a page but then changes their mind (by hitting the back button or by closing a tab), now when another user attempts to edit the same page; they're unable to save their own change without saving the previous user's "uncommitted" change. There doesn't appear to be any option to dismiss any previous pending/uncommitted changes and just apply your own i.e. it's an all or nothing situation

Suggestion

1) To have a dialog pop-up to tell the user to save/discard their change upon closing the tab or pressing back while in edit mode (just like Facebook).
2) To have a dialog pop-up when entering edit mode to save/discard a previous change that was neither saved or discarded before being allowed to continue.
3) While editing a page, if another user attempts to edit that same page to have a dialog pop-up to grant/deny consensual editing of that page by the third party.