Omit properties like "style" from this._propCaseMap.

Rearchitected Stateful to have a _getProps() method that returns all the properties
that should be watchable, or in other words, all the "official" properties.

_WidgetBase._getProps() has the code to only look at properties defined in the widget
definitions, thus ignoring properties in HTML*Element base classes.
Get Button working again after _Invalidating changes.
add note about use of eval
comment out tabIndex so Slider works on FF
reformat code
Revert "reformat code"

This reverts commit 09a58c8f0f466bc074074af773afddba49043817.
Auto-reformat of code to new coding standards.
Excluded dijit/, form/, layout/ and mobile/, plus generated CSS files.