Moved boxadder.css and html to client dir.
Implemented resizing for boxes and items.
- Added append/update functions for resize handles (which are ugly gray boxes right now). Called them in the sync and update functions for both boxes and items.
- Renamed the background rect css for both boxes and items to bounds-background for easier generic drag responding code that applies to both.
- syncAttrsToItems nows selects background rects with a css class just 'rect' to avoid catching the resize ahndle.
- Placed the item delete button using item.width rather than a static distance from the left side.
- Added drag behaviors for the resize handles that update width and height in the store and on the bounds-background element.