Add support for Sony DualShock 4 (manual merge of !160)

Files pulled in manually and code style changes, Gamepad type addition by Adam Honse <calcprogrammer1@gmail.com>

RGBController/RGBController.cpp

@@ -1416,6 +1416,8 @@ std::string device_type_to_str(device_type type)
         return "Headset";
     case DEVICE_TYPE_HEADSET_STAND:
         return "Headset Stand";
+    case DEVICE_TYPE_GAMEPAD:
+        return "Gamepad";
     default:
         return "Unknown";
     }

RGBController/RGBController.h

@@ -115,6 +115,7 @@ enum
     DEVICE_TYPE_MOUSEMAT,
     DEVICE_TYPE_HEADSET,
     DEVICE_TYPE_HEADSET_STAND,
+    DEVICE_TYPE_GAMEPAD,
     DEVICE_TYPE_UNKNOWN
 };