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/CounterBase.h

@@ -0,0 +1,33 @@
+/*----------------------------------------------------------------------------*/
+/* 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
+
+namespace frc {
+
+/**
+ * Interface for counting the number of ticks on a digital input channel.
+ * Encoders, Gear tooth sensors, and counters should all subclass this so it can
+ * be used to build more advanced classes for control and driving.
+ *
+ * All counters will immediately start counting - Reset() them if you need them
+ * to be zeroed before use.
+ */
+class CounterBase {
+ public:
+  enum EncodingType { k1X, k2X, k4X };
+
+  virtual ~CounterBase() = default;
+  virtual int Get() const = 0;
+  virtual void Reset() = 0;
+  virtual double GetPeriod() const = 0;
+  virtual void SetMaxPeriod(double maxPeriod) = 0;
+  virtual bool GetStopped() const = 0;
+  virtual bool GetDirection() const = 0;
+};
+
+}  // namespace frc