remove need for custom armel/armhf hacks; use libGL instead of GLESv1
remove Qt dep, allowing OSG to compile against libGL instead of GLESv1 (which is broken anyway) on armel and armhf, remove unnecessary ARM_DEFINES now that we can build on all platforms
Let's do this right the first time around. osgQt is no longer in plugins, long since deprecated so now there isn't a need for Qt support which was forcing GLESv1 support via armhf/armhl and breaks not only OSG demos (they don't work with GLESv1) it also breaks OpenMW on these arches.