Interface for widgets which can are used for editing cells
<gtk-cell-editable> interface must be implemented for widgets to be
usable when editing the contents of a
Begins editing on a cell-editable. event is the
<gdk-event>that began the editing process. It may be ‘
#f’, in the instance that editing was initiated through programatic means.
<gdk-event>, or ‘
Emits the "editing_done" signal. This signal is a sign for the cell renderer to update its value from the cell.