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/dev/java/edu/wpi/first/wpilibj/DevMain.java

@@ -0,0 +1,17 @@
+package edu.wpi.first.wpilibj;
+
+import edu.wpi.first.wpiutil.RuntimeDetector;
+import edu.wpi.first.wpilibj.hal.HALUtil;
+import edu.wpi.first.wpilibj.networktables.NetworkTablesJNI;
+
+public class DevMain {
+  /**
+   * Main entry point.
+   */
+  public static void main(String[] args) {
+    System.out.println("Hello World!");
+    System.out.println(RuntimeDetector.getPlatformPath());
+    System.out.println(NetworkTablesJNI.now());
+    System.out.println(HALUtil.getHALRuntimeType());
+  }
+}