function _makeMROFListEntry(path, pane, cursorPos) {
        return {
            file: path,
            paneId: pane,
            cursor: cursorPos
        };
    }
Creates an entry for MROF list
@private
@param {String} path - full path of a doc
@param {String} pane - the pane holding the editor for the doc
@param {Object} cursorPos - current cursor position
@return {Object} a frame containing file path, pane and last known cursor