facia tool: fake contentEditable

Use de-styled textareas for editable elements; make the focused one white. Bingo. 

![fronts-tool](https://cloud.githubusercontent.com/assets/1147913/4423948/ca170c84-4599-11e4-9186-d23090973c8e.png)

Also hides option indicators that have no effect (ie. imageHide, when there's no actual imageSrc)