Page design improvements.
Supporting HTML pages based only on JQuery (required for AJAX events).
Fixed HTML tag traversal (unmodifiable tags are ignored).
Fixed handling of unmodifiable tags (cannot assign context to them).
Improved session attribute retrieval (checking against null values).
Fixed generic page handler to use context.
Renamed "showcase" to "index" page and some clean-up in pages demo.
Refactored tag factory utils and added more attributes to some tags.
Added form and field factory utils.
Added demo page for forms.
Added more Bootstrap grid layout utils for convenience.
Redesigned core tag components and implemented tag cloning.
Added dropdown input field support.
Added multi-select input field support.
Added support for boolean tag attributes.
Added new tag attributes and fixed tag setters in the proxy.
Completed tag cloning implementation.
Added support for radio form input.