changed mac framer to be able to change panid during runtime
example:
#include "net/mac/framer-802154.h"
uint16_t panid = 1234;
framer_802154_set_panid(panid);

attention: this only changes the framer panid, you need to change
the radio panid too, e.g. with rf230_set_pan_addr on avr atmega128rfa1
changed slip-radio to be able to change panid over slip command
Merge branch 'master' of https://github.com/osdomotics/osd-contiki