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

wpilibj/src/test/java/edu/wpi/first/wpilibj/hal/JNITest.java

@@ -0,0 +1,25 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package edu.wpi.first.wpilibj.hal;
+
+import edu.wpi.first.wpilibj.networktables.NetworkTablesJNI;
+import org.junit.Test;
+
+public class JNITest {
+  @Test
+  public void jniNtcoreLinkTest() {
+    // Test to verify that the JNI test link works correctly.
+    NetworkTablesJNI.flush();
+  }
+
+  @Test
+  public void jniHalLinkTest() {
+    // Test to verify that the JNI test link works correctly.
+    HALUtil.getHALRuntimeType();
+  }
+}