Minimal coder code

Signed-off-by: Mathieu Cassard <mathieu.cassard@airtag.com>
utils : add MIN,MAX, pythagore, pseudo printf, DEBUG_PIN_ON/OFF and DUMP_VAR

Signed-off-by: Mathieu Cassard <mathieu.cassard@airtag.com>
odo : add odometry
(cleaned code from AVR asserv)

Signed-off-by: Mathieu Cassard <mathieu.cassard@airtag.com>