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

@DuaneGarber take aways:
* sign 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" >

    <input validate 
         required email 
         match="inputs.email" 
         type="text" 
         ng-model="inputs.confirm.email" 
         name="confirm email" >
    <!-- 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