paging done, needs some additional refactoring

front-api/controllers/common_for_controllers.rb

@@ -3,6 +3,10 @@ def get_querystring_hash()
    Rack::Utils.parse_nested_query(request.query_string)
 end
 
+def add_total_count_header(total)
+  response.headers['X-Total-Count'] = total
+end
+
 # converts list of parameters to array of integers
 def mass_to_i(*id_strings)
   id_strings.map(&:to_i)