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/CircularBuffer.h

@@ -0,0 +1,49 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015-2017. 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 <cstddef>
+#include <vector>
+
+namespace frc {
+
+/**
+ * This is a simple circular buffer so we don't need to "bucket brigade" copy
+ * old values.
+ */
+template <class T>
+class CircularBuffer {
+ public:
+  explicit CircularBuffer(size_t size);
+
+  void PushFront(T value);
+  void PushBack(T value);
+  T PopFront();
+  T PopBack();
+  void Resize(size_t size);
+  void Reset();
+
+  T& operator[](size_t index);
+  const T& operator[](size_t index) const;
+
+ private:
+  std::vector<T> m_data;
+
+  // Index of element at front of buffer
+  size_t m_front = 0;
+
+  // Number of elements used in buffer
+  size_t m_length = 0;
+
+  size_t ModuloInc(size_t index);
+  size_t ModuloDec(size_t index);
+};
+
+}  // namespace frc
+
+#include "CircularBuffer.inc"