Fixes a bug in init handler calling

GPIP Init handlers where never called
Broadcasts a packet if the dst MAC is not known
Removes static from get_output_handler (gpip)
Fixes bug introduced in d82e7b
Adds a request_packet_ou_call to smews gpip API

This can be used to make a call to the do_packet_out gpip handler
without waiting for a packet to come in. Can be used in timer or init function