add UI.Page
 + home page
 + ie-low-version-warning.js
mod core.models
 m add Index for User.name
 m set User.name unique
mod template/base.html, template/login/html
 m move global title to each page
mod template/home.html
 m reset home page
mod UI.Page
 + PageLogout
 + PageHome
mod UI.Page
 + PageRegister
verification code now can be reload with clicking the image
verification code now can be reload with clicking the image
prettify login page and register page