No OAuth Signup and Sign in Option #30

Hi @lipis!  I added a "sign in without a social network" button, a log in sign up template, and a hashing method to create a unique id based on email + password.  

https://github.com/gae-init/gae-init-auth/issues/30

Thanks for the opportunity, and I hope you approve :)
All the URLs are ending with trailing `/`