Bug 904 - GLJPanel: Allow user to skip isGLOriented() based vertical flip of offscreen backend

Add new GLJPanel method 'setSkipGLOrientationVerticalFlip(..)':

  /**
   * Set skipping {@link #isGLOriented()} based vertical flip,
   * which usually is required by the offscreen backend,
   * see details about <a href="#verticalFlip">vertical flip</a>
   * and <a href="#fboGLSLVerticalFlip">FBO / GLSL vertical flip</a>.
   * <p>
   * If set to <code>true</code>, user needs to flip the OpenGL rendered scene
   * <i>if {@link #isGLOriented()} == true</i>, e.g. via the PMV matrix.<br/>
   * See constraints of {@link #isGLOriented()}.
   * </p>
   */
  public final void setSkipGLOrientationVerticalFlip(boolean v) {

GearsES2: Handles 'flipVerticalInGLOrientation'

Unit test 'TestPerf001GLJPanelInit02AWT' validates and measures performance.