convert compare_files to the new st_printf functions

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
add a subnettool 'print' command; it just prints back the file passed as argument
but you can use the power of the '-fmt' option to print the field you want
space corrections on debug.h

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
update README

Signed-off-by: etienne basset <etienne.basset@numericable.fr>
upgrae README

Signed-off-by: etienne basset <etienne.basset@numericable.fr>