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/GearTooth.h

@@ -0,0 +1,37 @@
+/*----------------------------------------------------------------------------*/
+/* 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 <memory>
+#include <string>
+
+#include "Counter.h"
+
+namespace frc {
+
+/**
+ * Alias for counter class.
+ * Implement the gear tooth sensor supplied by FIRST. Currently there is no
+ * reverse sensing on the gear tooth sensor, but in future versions we might
+ * implement the necessary timing in the FPGA to sense direction.
+ */
+class GearTooth : public Counter {
+ public:
+  /// 55 uSec for threshold
+  static constexpr double kGearToothThreshold = 55e-6;
+  explicit GearTooth(int channel, bool directionSensitive = false);
+  explicit GearTooth(DigitalSource* source, bool directionSensitive = false);
+  explicit GearTooth(std::shared_ptr<DigitalSource> source,
+                     bool directionSensitive = false);
+  virtual ~GearTooth() = default;
+  void EnableDirectionSensing(bool directionSensitive);
+
+  std::string GetSmartDashboardType() const override;
+};
+
+}  // namespace frc