Use jiff for JSON diff/patch
Update buster, fix jshint warnings. Add Memory-test
Rewrite dom diffing, patching, registration.  Patching uses new DomBuilder, which is much cleaner, and registration uses a tree structure that is much faster to maintain and not noticeably slower for lookups when dealing with reasonable numbers of nodes (thousands).  Can still be improved, though.

Update todos demo app and server
Update bower.json to point to document-sync branch