style(filename) change file name having not appropriate

change specfile's name which not respond to original file like that
- lib/directive/a_href.dart
- test/directive/ng_a_spec.dart

Closes #1340
fix(form example): type() has been replaced by bind()
fix(form example): watched collections can not be mutated
refactor(form example): update the directory structure
refactor(form example): html & dart cleanup

Closes #1373
feat(examples): Add a compelling Shadow DOM example

Conflicts:
	example/web/index.html

Closes #1377
perf(view_factory): add a benchmark that measures view_factory in isolation

Closes #1384