UI Improvements

Various UI improvements.

Edit JSON in a pop-up modal.  Disable object while editing.  Use Ace editor if available.

![editjson](https://cloud.githubusercontent.com/assets/1087514/2624473/2b7b98fa-bd41-11e3-91c6-2b227b80d17c.png)

Consolidate Add Property and remove property links into a pop-up modal.  Disable object while the modal is open.

![properties](https://cloud.githubusercontent.com/assets/1087514/2624475/64e1c272-bd41-11e3-9a69-da0480022a6e.png)

Use grids to layout the form.  Strings get 4 columns.  Integers and numbers get 2 columns.  Textareas and code editors get 6 columns.  Objects and arrays get 12 columns.  Tables will be either 6 or 12, depending on their complexity.

![](http://designpotato.com/wp-content/uploads/2013/08/Pure-CSS3-Forms-Set.jpg)

More consistent treatment of labels and headers.  Right now objects and arrays use huge H3 text and other editors use normal paragraph text.  This makes objects with both types of properties look bad.

![labels](https://cloud.githubusercontent.com/assets/1087514/2624510/bfb31166-bd45-11e3-9730-879270e5bba9.png)

The multiple and enum  editors look bad.  The switcher element is hard to see on the right side and the border around the element makes it look set apart from the other fields.

![switcher](https://cloud.githubusercontent.com/assets/1087514/2624518/7af27246-bd46-11e3-8fef-bff815ff7f81.png)