Impelements and integrates DisplayFactory. Further does some refactoring

FlippR-Driver/src/output/factories/ItemFactory.h

@@ -24,13 +24,25 @@ namespace config_path
   const char item_address[] = "address";
   const char item_extender[] = "extender";
   const char item_identifier[] = "id";
+  const char port_extenders[] = "port_extenders";
 
   const char deactivation_time[] = "deactivation_time_milliseconds";
+
   const char sound_path[] = "sounds";
+  const char fire_pin[] = "fire_pin";
+  const char sound_address_pins[] = "address_pins";
 
   const char flipper_path[] = "flippers";
 
   const char solenoid_path[] = "solenoids";
+
+  const char display_board[] = "display_board";
+  const char run_pin[] = "run";
+  const char display_select[] = "display_select";
+  const char display_segement_select[] = "segment_select";
+  const char display_digit_select[] = "digit_select";
+  const char display_digits[] = "digits";
+  const char display_list[] = "displays";
 }
 
 class ItemFactory