Switch DS Sim Sockets to use UV loops (#1211)

Also adds the simulation packet to force switch the DS to local.

simulation/halsim_ds_socket/src/dev/native/cpp/main.cpp

@@ -0,0 +1,18 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2018 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include <thread>
+
+#include <hal/HAL.h>
+#include <wpi/raw_ostream.h>
+
+extern "C" int HALSIM_InitExtension(void);
+
+int main() {
+  HAL_Initialize(500, 0);
+  HALSIM_InitExtension();
+}