focus.js simplifications, forward ports, and reduction in dependence on dojo core.
focus.js simplifications, forward ports, and reduction in dependence on dojo core.

1. Get rid of focus.curNode/prevNode; can just use document.activeElement.
2. Change API to see new widget stack from watch() to on().
3. Use native methods rather than dom.byId(), domAttr.get(), winUtils.get().
4. refactor, cherry picked from dijit b24525552996dee6c41e299df5f995ba91953b91
5. support for pointer events, cherry picked from dijit 2dcb4e325792caca5bd4ee053a8d7e390c619fff but not using has("...")

Sam-Cummins/delite,harbalk/delite,kitsonk/delite,kitsonk/delite,Sam-Cummins/delite,harbalk/delite