Infrastructure changes to fire custom tabIndex setter (this.tabIndex = 3) on Safari.  To get the tabIndex value, use this._get("tabIndex") instead of this.tabIndex
delete doh tests replaced by intern ones
more fixes for native document.register() support
fix handlebars when browser supports document.register() natively
Rewrite test to work on browser w/native document.register() support.
Need to handle case where elements are upgraded before the upgrade() call.