remove (probably accidently comitted) write_node/read_node function declaration
remove (probably accidently comitted) write_node/read_node function declaration

[r15862]

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