Site setting to allow mods to create categories

config/locales/server.en.yml

@@ -656,6 +656,7 @@ en:
     ga_universal_domain_name: "Google Universal Analytics (analytics.js) domain name, eg: mysite.com; see http://google.com/analytics"
     enable_escaped_fragments: "Fall back to Google's Ajax-Crawling API if a crawler is not detected."
     enable_noscript_support: "Enable standard webcrawler search engine support via the noscript tag"
+    allow_moderators_to_create_categories: "Allow moderators to create new categories"
     top_menu: "Determine which items appear in the homepage navigation, and in what order. Example latest|new|unread|starred|categories|top|read|posted"
     post_menu: "Determine which items appear on the post menu, and in what order. Example like|edit|flag|delete|share|bookmark|reply"
     share_links: "Determine which items appear on the share dialog, and in what order. Example twitter|facebook|google+|email"

config/site_settings.yml

@@ -345,6 +345,7 @@ security:
   enable_escaped_fragments: true
   allow_index_in_robots_txt: true
   enable_noscript_support: true
+  allow_moderators_to_create_categories: false
 
 onebox:
   enable_flash_video_onebox: false

lib/guardian/category_guardian.rb

@@ -2,7 +2,7 @@
 module CategoryGuardian
   # Creating Method
   def can_create_category?(parent)
-    is_admin?
+    is_admin? || (SiteSetting.allow_moderators_to_create_categories && is_moderator?)
   end
 
   # Editing Method