Fix HTMLInputElement.prototype.checked per html spec
Fix HTMLOptionElement.prototype.selected per spec
Fix HTMLInputElement.prototype.value per spec
Fix HTMLTextAreaElement.prototype.value per spec
Two new methods _descendantAdded  and _descendantRemoved on Node

Certain child classes will override these to be notified of changes in the node tree.
Fix "asking for a reset" for select/option elements per html spec
Implement the form reset algorithms for the various fields
Uncheck "other" radio fields at the proper conditions per spec