Add class for Ray's check-box

Fix some typos
Change the default index for auth
Add some hard code in object_auth.rb to handle page_context
A user cannot select himself in authorisation

lib/orbit_category/categorizing.rb

@@ -9,7 +9,7 @@ module OrbitCategory
       end
     end
 
-    def get_categories_for_form(func_authed_for_sub_manager = "submit_#{@module_app.key}")
+    def get_categories_for_form(func_authed_for_sub_manager = "category_#{@module_app.key}")
       categories = if is_manager? || is_admin?
         @module_app.categories.enabled
       elsif is_sub_manager?