refactor(binder): move _addRefs() to ElementBinderBuilder.addAllDirectives()

Also remove key(Type) from the Directive ref ctor parameter as this can
be constructed from the given type argument
refactor(binder): node argument moved from DirectiveRef to ElementBinderBuilder ctor
style: Dart CS
refactor(selector regexp): update the selector regexp

The new regexp is easier to understand and marginally faster (~5%)
doc(compiler): improve online doc
style: Dart CS
refactor(ViewFactory): simplify the code
refactor(ViewFactory): Simplify the code as @Controller is gone