BugFix: get_next_neighbour(): free the nodeset allocated in the iterator when next steps outside:
BugFix: get_next_neighbour(): free the nodeset allocated in the iterator when next steps outside:

[r13475]

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