Add support for setting initial node number through debugging extension.
Add support for setting initial node number through debugging extension.

This also supports setting the initial node number to "rand", thereby
replacing randnodenr.

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