Split decoding return code GTP_RC_PDU in GTP_RC_PDU_C and GTP_RC_PDU_U.
Don't do IEs in GTP_RC_PDU_U.
Add a unit test for User plane data, expected to fail (nonstandard port case).
In gtphub_test.c, tweak logging so that it is easily visible which test
produced which output. Also add the global resolved_sgsn_addr and ggsn_sender,
symmetrically to resolved_ggsn_add and sgsn_sender.
Sponsored-by: On-Waves ehi
Neels Hofmeyr
e921e32c82