SceneGraph: shorten lengthy test names to preserve 80-column ctest output.
SceneGraph: shorten lengthy test names to preserve 80-column ctest output.

As we now have 100 tests (yay!), ctest needs three more characters to
display the progress, thus we need to shorten the long test names a bit
more. Should suffice for a long time, I'm not planning to have >999
tests :-)

DerThorsten/magnum,DerThorsten/magnum,ashimidashajia/magnum,ashimidashajia/magnum,ashimidashajia/magnum,DerThorsten/magnum,MiUishadow/magnum,MiUishadow/magnum,MiUishadow/magnum,DerThorsten/magnum,DerThorsten/magnum,MiUishadow/magnum,ashimidashajia/magnum,ashimidashajia/magnum,MiUishadow/magnum,MiUishadow/magnum