Update to 2018_v4 image and new build system. (#598)

* Revert "Force OpenCV to 3.1.0 (#602)"

This reverts commit 50ed55e8e2.

* Removes Simulation

* Removes old build system

* Removes old gtest

* Adds new gmock and gtest

* Updates to new ni-libraries

* removes MyRobot (to be replaced)

* moves files to new location

* Adds new sim backend and new test executables

* updates .styleguide and .gitignore

* Changes cpp WPILibVersion to a function

MSVC throws an AV with the old version.

* Disables USBCamera on all systems except for linux

* 2018 NI Libraries

* New build system

hal/src/main/native/include/HAL/cpp/fpga_clock.h

@@ -0,0 +1,32 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2017. 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <chrono>
+#include <limits>
+
+namespace hal {
+
+class fpga_clock {
+ public:
+  typedef std::chrono::microseconds::rep rep;
+  typedef std::chrono::microseconds::period period;
+  typedef std::chrono::microseconds duration;
+  typedef std::chrono::time_point<fpga_clock> time_point;
+
+  static fpga_clock::time_point now() noexcept;
+  static constexpr bool is_steady = true;
+
+  static constexpr fpga_clock::time_point epoch() { return time_point(zero()); }
+
+  static constexpr fpga_clock::duration zero() { return duration(0); }
+
+  static constexpr time_point min_time{
+      time_point(duration(std::numeric_limits<duration::rep>::min()))};
+};
+}  // namespace hal