Formated code with go fmt

Run go fmt on the modelsGae.go
Update callback definition in controllers.go

Changed u User to u *User.
Let callback to change user for other logics
Renamed modelsGae

I think GAE is easier to read and understand
Various changes in controllers

1. Migrated the User definition to models.go to better organize
2. Finished registration logic
Update DefaultRegisterCallback and fmt

1. Update DefaultRegisterCallback to record Created and Updated date
2. git fmt on the codes
Basic GAE register, login and logout ready

Basic user creation, login and logout ready