Add ability to end startCompetition() main loop (#2032)

This is useful for both cleanly exiting from simulation and for unit testing
at a framework level.

This change required removing move constructor/assignment from IterativeRobot.

wpilibc/src/main/native/include/frc/DriverStation.h

@@ -394,6 +394,11 @@ class DriverStation : public ErrorBase {
    */
   void InTest(bool entering) { m_userInTest = entering; }
 
+  /**
+   * Forces WaitForData() to return immediately.
+   */
+  void WakeupWaitForData();
+
  protected:
   /**
    * Copy data from the DS task for the user.