support %P  in st_scanf

Signed-off-by: etienne <etienne.basset@ensta.org>
update st_vscanf

Signed-off-by: etienne <etienne.basset@ensta.org>
st_scanf : add support for %M (MASK)

Signed-off-by: etienne <etienne.basset@ensta.org>
make any conversion modifier illegal after '%s'
make %P use find_ip and %M use find_int for string ending

Signed-off-by: etienne <etienne.basset@ensta.org>
typo in scanning mask

Signed-off-by: etienne <etienne.basset@ensta.org>
update test for scanf

Signed-off-by: etienne <etienne.basset@ensta.org>
clean up get_single_ipv4
make string2mask not copy its input string

Signed-off-by: etienne <etienne.basset@ensta.org>
more get_single_ipv6 clean up

Signed-off-by: etienne <etienne.basset@ensta.org>
add a regtest for weird and malformed IP handling

Signed-off-by: etienne <etienne.basset@ensta.org>
get_subnet_or_ip : dont print redundant invalid ip DEBUG mesg

Signed-off-by: etienne <etienne.basset@ensta.org>
make get_subnet_or_ip get addr directly into subnet->ip_addr to avoid a useless copy

Signed-off-by: etienne <etienne.basset@ensta.org>