Merge pull request #28 from cpaasch/master

support socket_fd on icmp messages
It fixes #26. Apparently, sockets 6 and 7 are used for sslclients thus
sockets 6 and 7 could not be used for our tests. 

Need to be confirmed about 'sslclients'.
Fix some tests

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Merge branch 'mypdrill' into more_tests

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>

Conflicts:
	gtests/net/packetdrill/examples/mptcp/mp_join/mp_join_packd_to_kernel_ipv6.pkt_not_working
Move