Youido improvements

[glutamate]

• Remove dependency on scotty and create a wai application instead
• Support for DB pools
• custom 404/500 handler
• support for custom session storage so we could use something persistent like redis
• two factor authentication with the Google authenticator app
• updating pages with PJAX
• support for modals where content is sent via html over ajax.

[balajirrao]

@glutamate, regarding "Support for DB pools", what exactly do you have in mind ? Since Youido never deals with DBs is confusing me.

Also, regarding "custom 404/500 handler", we have , _notFoundHtml :: Html () in below, which would count as a custom 404 handler ?

data Youido auth m = Youido
  { _handlers :: [Handler m] -- ^ list of handlers
  , _notFoundHtml :: Html () -- ^ default, if nothing found
  , _wrapper :: auth -> (Html () -> Html ()) -- ^ wrapper for Html
  , _lookupUser:: Request -> Email-> ByteString-> IO (Maybe auth)
  , _port :: Int
  }