fixed assignement of stack register added callbacks for spill- and reload-lowering
fixed assignement of stack register
added callbacks for spill- and reload-lowering

jonashaag/libfirm,killbug2004/libfirm,MatzeB/libfirm,davidgiven/libfirm,libfirm/libfirm,libfirm/libfirm,MatzeB/libfirm,killbug2004/libfirm,killbug2004/libfirm,libfirm/libfirm,8l/libfirm,davidgiven/libfirm,libfirm/libfirm,MatzeB/libfirm,8l/libfirm,MatzeB/libfirm,jonashaag/libfirm,jonashaag/libfirm,killbug2004/libfirm,jonashaag/libfirm,davidgiven/libfirm,jonashaag/libfirm,MatzeB/libfirm,jonashaag/libfirm,killbug2004/libfirm,8l/libfirm,killbug2004/libfirm,8l/libfirm,8l/libfirm,jonashaag/libfirm,davidgiven/libfirm,8l/libfirm,killbug2004/libfirm,MatzeB/libfirm,davidgiven/libfirm,MatzeB/libfirm,davidgiven/libfirm,davidgiven/libfirm,libfirm/libfirm,8l/libfirm