Add 'apple touch icon url' site setting

app/models/site_setting.rb

@@ -80,6 +80,7 @@ class SiteSetting < ActiveRecord::Base
   setting(:active_user_rate_limit_secs, 60)
   setting(:previous_visit_timeout_hours, 1)
   setting(:favicon_url, '/assets/default-favicon.png')
+  setting(:apple_touch_icon_url, '/assets/default-apple-touch-icon.png')
 
   setting(:ninja_edit_window, 5.minutes.to_i)
   setting(:post_undo_action_window_mins, 10)

app/views/layouts/application.html.erb

@@ -10,6 +10,7 @@
     <%= canonical_link_tag %>
 
     <link rel="icon" type="image/png" href="<%=SiteSetting.favicon_url%>">
+    <link rel="apple-touch-icon" type="image/png" href="<%=SiteSetting.apple_touch_icon_url%>">
     <%= javascript_include_tag "preload_store" %>
 
     <%= render :partial => "common/special_font_face" %>

config/locales/server.en.yml

@@ -459,6 +459,8 @@ en:
     logo_url: "The logo for your site eg: http://example.com/logo.png"
     logo_small_url: "The small logo for your site used when scrolling down on topics eg: http://example.com/logo-small.png"
     favicon_url: "A favicon for your site, see http://en.wikipedia.org/wiki/Favicon"
+    apple_touch_icon_url: "Icon used for Apple touch devices. Recommended size is 144px by 144px."
+
     notification_email: "The return email address used when sending system emails such as notifying users of lost passwords, new accounts etc"
     use_ssl: "Should the site be accessible via SSL? (NOT IMPLEMENTED, EXPERIMENTAL)"
     best_of_score_threshold: "The minimum score of a post to be included in the 'best of'"