protos: lldp: Add LLDP dissector to netsniff-ng

The order and presence of the mandatory TLVs is not yet completely
checked. Also the Management Address is not yet implemented.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Merge remote-tracking branch 'borkmann/master' into lldp

Conflicts:
	src/dissector_eth.c
dissector: lldp: print number of TLV in less print mode

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
dissectors: lldp: Implement dissection of Management Address TLV

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
tprintf: xutils: Move tput*_safe to tprintf.c

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Merge branch 'master' of github.com:borkmann/netsniff-ng into lldp
dissectors: lldp: check for all mandatory TLVs at correct position

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
dissectors: lldp: Highlight invalid frame marker

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>