Object.observe support

[anthonyshort]

Update ripple/path-observer to use Object.observe if it's available.

[tarqd]

Would you be open to using observe-js for this? It already uses Object.observe if available and implements the LCS algorithm that we talked about on the ripplejs/each issue

[anthonyshort]

Yeah I'd probably just use that library. I haven't had much need for it yet though. I think the only real benefit is a possible slight performance boost.