Test: Don't resize frame, tweek print-matrix; AWTPrintLifecycle: Add scale and convenient AWT container traversal context; GLCanvas/GLJPanel properly handle existing MSAA and req. AA;

- Test: Don't resize frame, tweek print-matrix
  - Use scaleComp72 to scale the frame to fit on page,
    i.e. global print matrix

  - Use scaleGLMatXY = 72.0 / glDPI
    to locally scale on the GL drawable as being passed to AWTPrintLifecycle.setup(..)

  - Hence frame stays untouched/stable, no need for 'offscreen' print test,
    which is removed.

- AWTPrintLifecycle: Add scale and convenient AWT container traversal context
  Use a simple decoration for all AWTPrintLifecycle impl. components within a container:

    final AWTPrintLifecycle.Context ctx = AWTPrintLifecycle.Context.setupPrint(frame, g2d, scaleGLMatXY, scaleGLMatXY);
    try {
    } finally {
       ctx.releasePrint();
    }

- GLCanvas/GLJPanel properly handle existing MSAA and req. AA;
  - GLCanvas: Workaround bug where onscreen MSAA cannot switch to offscreen FBO,
              i.e. stay 'onscreen'
  - GLJPanel: Use new offscreen FBO if MSAA is requested and not yet used.

- GLJPanel.Offscreen.postGL(): always swapBufer(), was missing for !GLSL swapping

Results GLCanvas / GLJPanel:
  - Good scaling
  - Stable behavior / visibility
  - High DPI mode works