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/sim/MockData/HALValueInternal.h

@@ -0,0 +1,27 @@
+/*----------------------------------------------------------------------------*/
+/* 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 <memory>
+#include <string>
+
+#include "MockData/HALValue.h"
+#include "MockData/llvm/StringRef.h"
+
+namespace hal {
+
+class Value;
+
+void ConvertToC(const Value& in, HAL_Value* out);
+std::shared_ptr<Value> ConvertFromC(const HAL_Value& value);
+void ConvertToC(llvm::StringRef in, HALString* out);
+inline llvm::StringRef ConvertFromC(const HALString& str) {
+  return llvm::StringRef(str.str, str.len);
+}
+
+}  // namespace hal