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

wpilibc/src/main/native/include/Timer.h

@@ -0,0 +1,57 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2008-2017. 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 "Base.h"
+#include "HAL/cpp/priority_mutex.h"
+
+namespace frc {
+
+typedef void (*TimerInterruptHandler)(void* param);
+
+void Wait(double seconds);
+double GetClock();
+double GetTime();
+
+/**
+ * Timer objects measure accumulated time in seconds.
+ * The timer object functions like a stopwatch. It can be started, stopped, and
+ * cleared. When the timer is running its value counts up in seconds. When
+ * stopped, the timer holds the current value. The implementation simply records
+ * the time when started and subtracts the current time whenever the value is
+ * requested.
+ */
+class Timer {
+ public:
+  Timer();
+  virtual ~Timer() = default;
+
+  Timer(const Timer&) = delete;
+  Timer& operator=(const Timer&) = delete;
+
+  double Get() const;
+  void Reset();
+  void Start();
+  void Stop();
+  bool HasPeriodPassed(double period);
+
+  static double GetFPGATimestamp();
+  static double GetPPCTimestamp();
+  static double GetMatchTime();
+
+  // The time, in seconds, at which the 32-bit FPGA timestamp rolls over to 0
+  static const double kRolloverTime;
+
+ private:
+  double m_startTime = 0.0;
+  double m_accumulatedTime = 0.0;
+  bool m_running = false;
+  mutable hal::priority_mutex m_mutex;
+};
+
+}  // namespace frc