Merge branch 'auth-icons-labels' into 'master'

Allow custom label to be set for authentication providers.

Addresses internal issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2341

Beside the above, I've:
- Refactored `OauthHelper` to have clearer method names and behaviour
- Moved some of `OauthHelper` behaviour to `Gitlab::OAuth::Provider`
- Renamed `OauthHelper` to `AuthHelper` since LDAP, SAML, Kerberos aren't OAuth
- Updated the icons for GitHub and GitLab

In the examples below, "OurAuth" is a SAML provider with a custom label.

![Screen_Shot_2015-07-02_at_16.29.52](https://gitlab.com/gitlab-org/gitlab-ce/uploads/7d425bde69dc34e1667ebd5375d0266d/Screen_Shot_2015-07-02_at_16.29.52.png)

![Screen_Shot_2015-07-02_at_16.31.40](https://gitlab.com/gitlab-org/gitlab-ce/uploads/cbb273321ecdf4cab3d3ef0dc35553e7/Screen_Shot_2015-07-02_at_16.31.40.png)

![Screen_Shot_2015-07-02_at_16.32.39](https://gitlab.com/gitlab-org/gitlab-ce/uploads/d8dd6e1d0dc45a788e869cdcdc99e178/Screen_Shot_2015-07-02_at_16.32.39.png)

![Screen_Shot_2015-07-02_at_16.33.18](https://gitlab.com/gitlab-org/gitlab-ce/uploads/7dbfe8b0ae229c32a08d6c7442976d83/Screen_Shot_2015-07-02_at_16.33.18.png)


See merge request !927

1 files changed, 20 insertions, 8 deletions

diff --git a/lib/gitlab/o_auth/provider.rb b/lib/gitlab/o_auth/provider.rb
index f986499a27c..90c3fe8da33 100644
--- a/lib/gitlab/o_auth/provider.rb
+++ b/lib/gitlab/o_auth/provider.rb
@@ -1,18 +1,30 @@
 module Gitlab
   module OAuth
     class Provider
-      def self.names
-        providers = []
+      def self.providers
+        Devise.omniauth_providers
+      end
 
-        Gitlab.config.ldap.servers.values.each do |server|
-          providers << server['provider_name']
-        end
+      def self.enabled?(name)
+        providers.include?(name.to_sym)
+      end
 
-        Gitlab.config.omniauth.providers.each do |provider|
-          providers << provider['name']
+      def self.ldap_provider?(name)
+        name.to_s.start_with?('ldap')
+      end
+
+      def self.config_for(name)
+        name = name.to_s
+        if ldap_provider?(name)
+          Gitlab::LDAP::Config.new(name).options
+        else
+          Gitlab.config.omniauth.providers.find { |provider| provider.name == name }
         end
+      end
 
-        providers
+      def self.label_for(name)
+        config = config_for(name)
+        (config && config['label']) || name.to_s.titleize
       end
     end
   end