filediff, ui.statubar: Remove overwrite mode indicator
Text editors seem split on whether to show one of these. Some (gedit, LibreOffice Writer) do, others (Builder, Sublime Text) just rely on the insert cursor changing to a block. Given that I see overwrite mode as basically a giant historical misfeature, and also that I don't really want to move the display code over to the new status bar... I'm going to remove the display of it.
Showing with 0 additions and 27 deletions