observe properties via compound path observer.
remove deprecated code.
adapt to new CompoundPathObserver api.
- Merge branch 'master' into compoundpathobserver
- custom property observer methods
- de-duping of property observers
- subpath property observers
Merge branch 'master' into compoundpathobserver
Test functions now under polyfill since https://github.com/Polymer/ShadowDOM/issues/189 is fixed.
observe block tests
simplify test slightly.