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/shared/cpp/fpga_clock.cpp

@@ -0,0 +1,28 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "HAL/cpp/fpga_clock.h"
+
+#include "HAL/HAL.h"
+#include "llvm/raw_ostream.h"
+
+namespace hal {
+constexpr fpga_clock::time_point fpga_clock::min_time;
+
+fpga_clock::time_point fpga_clock::now() noexcept {
+  int32_t status = 0;
+  uint64_t currentTime = HAL_GetFPGATime(&status);
+  if (status != 0) {
+    llvm::errs()
+        << "Call to HAL_GetFPGATime failed."
+        << "Initialization might have failed. Time will not be correct";
+    llvm::errs().flush();
+    return epoch();
+  }
+  return time_point(std::chrono::microseconds(currentTime));
+}
+}  // namespace hal