Fix UIManager's reference to Pile container() function.

Signed-off-by: Zach Bennett <xslingshot@gmail.com>
Scope event listeners in app.js.

Signed-off-by: Zach Bennett <xslingshot@gmail.com>
Minor cleanup.

Signed-off-by: Zach Bennett <xslingshot@gmail.com>
Implement basic Mat.

Signed-off-by: Zach Bennett <xslingshot@gmail.com>
Remove unused event definitions.

Signed-off-by: Zach Bennett <xslingshot@gmail.com>
Add basic drag and drop support between Cards and Piles.

Signed-off-by: Zach Bennett <xslingshot@gmail.com>