Merge branch 'improve-login-page' into 'master'

Improve login page

* use max-width for brand logo to prevent stretch of small images
* improve default brand logo to be centred on any kind of screen
* hide logo for small screens
* hide text for xs screens
* reduce amount of text on sign-in page

Fixes #1423

See merge request !966

app/assets/stylesheets/sections/login.scss

@@ -9,9 +9,9 @@
   }
   .brand-image {
-    margin-bottom:  20px;
     img {
-      width: 100%;
+      max-width: 100%;
+      margin-bottom:  20px;
     }
   }

app/helpers/appearances_helper.rb

 module AppearancesHelper
+  def brand_item
+    nil
+  end
+
   def brand_title
     'GitLab Community Edition'
   end
   def brand_image
-    image_tag 'brand_logo.png'
+    nil
   end
   def brand_text
-    default_text =<<eos
-### GitLab is open source software to collaborate on code.
-
-Manage git repositories with fine grained access controls that keep your code secure.
-Perform code reviews and enhance collaboration with merge requests.
-Each project can also have an issue tracker and a wiki.
-
-Used by more than 100,000 organizations, GitLab is the most popular solution to manage git repositories on-premises.
-Read more about GitLab at [about.gitlab.com](https://about.gitlab.com/).
-eos
-    markdown default_text
+    nil
   end
 end

app/views/layouts/devise.html.haml

@@ -12,10 +12,22 @@
       .content
         .row
           .col-md-7
-            .brand-image
-              = brand_image
-            .brand_text
-              = brand_text
+            - if brand_item
+              .brand-image
+                = brand_image
+              .brand_text
+                = brand_text
+            - else
+              .brand-image.hidden-sm.hidden-xs
+                = image_tag 'brand_logo.png'
+              .brand_text.hidden-xs
+                %h2 Open source software to collaborate on code
+
+                %p.lead
+                  Manage git repositories with fine grained access controls that keep your code secure.
+                  Perform code reviews and enhance collaboration with merge requests.
+                  Each project can also have an issue tracker and a wiki.
+
           .col-md-5
             = yield
     %hr