refactor(forms): Even better forms

- remove $formFactory completely
- remove parallel scope hierarchy (forms, widgets)
- use new compiler features (widgets, forms are controllers)
- any directive can add formatter/parser (validators, convertors)

Breaks no custom input types
Breaks removed integer input type
Breaks remove list input type (ng-list directive instead)
Breaks inputs bind only blur event by default (added ng:bind-change directive)