Auth

Existing issues:
1. Refresh page will clean up in-memory token, thus force user logout.
2. Signup should automatically login the user
3. No client form validation

Once checkin this pr, I'll create issues for these in case I forget.


![screen shot 2014-08-31 at 12 56 30 am](https://cloud.githubusercontent.com/assets/1242553/4101370/f6b3f53c-30e4-11e4-828a-f84061da16ec.png)

![screen shot 2014-08-31 at 12 56 39 am](https://cloud.githubusercontent.com/assets/1242553/4101374/26910e8e-30e5-11e4-986d-9cb3a19d96e2.png)

![screen shot 2014-08-31 at 12 56 52 am](https://cloud.githubusercontent.com/assets/1242553/4101377/2a1779bc-30e5-11e4-823c-6b0c44879d56.png)