Arrow keys, SPACE, and Page Up/Down are not passed to contentEditable elements in the view-issue page

When the target of a keyboard event is content-editable, the stalker-bar consumes space/pageup/pagedown (stalker.js), and dialog-scroll control (AJS.disableKeyboardScrolling) consumes the arrow keys.

Both currently attempt to let keyboard events pass through to inputs/textareas, but they also need to pass the events to any contentEditable element.