chuck git version at the bottom of the page

app/views/layouts/application.html.erb

@@ -58,5 +58,6 @@
     <%= render :partial => "common/discourse_javascript" %>
     <%= render_google_analytics_code %>
 
+    <!-- Git Version: <%= $git_version %> -->
   </body>
 </html>

lib/discourse.rb

@@ -44,6 +44,14 @@ module Discourse
     !!$redis.get( maintenance_mode_key )
   end
 
+  def self.git_version
+    begin
+      $git_version ||= `git rev-parse HEAD`
+    rescue
+      $git_version = "unknown"
+    end
+  end
+
 
 private