Scripts: Adapt finding gluegen ..
Fix regression of 31e72d2f2d953352b2a8c83368039ecca8139d49: Modifier SHIFT needs to be recognized (-> horiz. scroll)
Fix Bug 735: GLAutoDrawable must issue glViewport(..) even w/o GLEventListener ; Optimize GLDrawableHelper's glViewportCall(..)

GLAutoDrawable must issue glViewport(..) even w/o GLEventListener
 - Same behavior w/ or w/o GLEventListener requires to issue glViewport, always.

Optimize GLDrawableHelper's glViewportCall(..)
  - 'private void init(..)' receives 'setViewport' argument to be passed to 'private void reshape(..)'
    allowing to only the the viewport once @ 'public void init(..)' and display.