Omniauth Support
Created by: funglaub
Hey guys.
First of all, thanks for the great app!
I added Omniauth support for Google-OAuth2, Twitter and GIthub to gitlab.
It works like that: A user can choose between pre-configured omniauth providers to login along with his username/password. This can be found in the 'Authentications' (the former 'Password') tab.
Configuration is done in config/gitlab.yml, including app_id and app_secret for each provider. The list of providers can easily be expanded by adding the needed gems to the Gemfile and providing a corresponding logo. The current logos were taken from http://github.com/intridea/authbuttons.
Omniauth can also be disabled in config/gitlab.yml, which is the current default setting.
I tried to integrate all the new functionality as good as possible into existing views.
Please, tell me what you think!