Fixes dependencies
Refactor some JS. Patchwork is now an object with a root VNode and its corresponding place in the DOM
Remove key field from Text
Add count field to Elem
Almost rewrote diffing algorithm. Much better.

* diff(a::Node, b::Node) - pure function returns a list of patches
* diff!(a,b,index,patches) - appends patches to patches arg
* exact correspondence of node indices to those in virtual-dom"
A bunch of code to test out and compare diffs inside IJulia