Add null draggingPath to starting state
Enable React devtools
Columns no longer dissappear when empty
Columns receive correct cards and flip over uncovered cards
Foundation receives correct cards
Foundation can only receive one card at a time
SVG cards from https://code.google.com/p/vectorized-playing-cards/

Transformed with a bash script to add a viewBox which crops them
to size.
Don't swap containers between Draggable and DropTarget

This cause the DOM subtrees to be discarded and reloaded, which
resulted in a flicker as the <img> for the faces redownloaded.

Reloading the subtree is an artifact of how Reconciliation works
in React. This is my second run-in with Draggable and DropTarget
and Reconciliation (ff7e6fdc4807ed8ee2d552098358b2ff036e012f).

The solution here is to merge the two classes together, to create
`DragAndDrop`. It inspects the properties to determine which
behaviors are active. The Board top-level function `containerForCard`
has been replaced with `isCardDraggable` and `isCardDropTarget`, which
are called by Stack. Every stack is now a `DragAndDrop`, where as
before some cards would be plain `div`s.
Stacks now extend upwards in Z space

This appears to alleviate some drag and drop interaction issues
(probably z fighting) while also giving the stacks a nice 3D
appearance.
Draw pile now has an outline when empty