Fixed broken DOM subscription facades, when the Y instance was set to
emitFacade:true

If emitFacade for the Y instance was set to true, listeners for DOM events
would receive a Y.EventFacade instance, rather than a Y.DOMEventFacade
instance, and the target and currentTarget would be set to the Y instance,
instead of the expected Y.Node instance.

Original pull request and fix (https://github.com/yui/yui3/pull/480) thx
to @natecavanaugh

This commit just adds unit tests, and confirms the root issue impacts all
DOM events (not just focus).

All Test Pass:
✔ [Total]: Passed: 10863 Failed: 0 Total: 10958 (ignored 95)

Also ran dom.html unit tests on Chrome, FF, Safari/Mac, Safari/iOS, IE8.
Rewrote the test, to avoid changing the emitFacade setting on the Y instance
used by the other tests.
Merge branch 'Y-instance-emitFacade' into dev-master
Minor, non-functional cleanup: removed an unused
Build for Y instance emitFacade DOM event fix.

All tests pass through yogi test --no-cli (apart from the currently
failing throttle test).

Also the dom.html tests pass on Safari, FF, Chrome, iOS, IE6, IE8.