Implemented signin, added fields to signup, implemented email, password and match directives

@DuaneGarber take aways:
* sing in in works
* `password` directive now validates using the password regex constant set in the app.js file 
* `email` directive now validates using the email regex constant set in the app.js file 
* `match` directive now takes an `ng-model` object chain on which to bind. if the inputs do not match, the validator will display an error. unfortunately, you still need a model to run these directives, so a no-op model is used

directives in action:

```html
  <form novalidate>
      <input validate required email type="text" ng-model="inputs.email" name="email" placeholder="Email Address">
      <input validate required email match="inputs.email" type="text" ng-model="inputs.confirm.email" name="confirm email" placeholder="Confirm Email Address">
      <!-- replace email with password to see that directive in operation-->
  </form>
```

it seems like every time i try to use as little jquery as possible i end up with a weird frankenstein directive :/ Its not the end of the world, it makes me feel a little silly though. fortunately, jquery in directives isnt the end of the world, its jquery in controllers that everyone gets up in arms about