HIG  - remove Revert standard menu item

It's confusing. Undo is better.

https://bugzilla.gnome.org/show_bug.cgi?id=107716
HIG - keyboard shortcuts, tidy up an oops
HIG - remove menu items for file versioning

They are not really used, and don't exactly represent The Future.

https://bugzilla.gnome.org/show_bug.cgi?id=737600