Merge remote-tracking branch 'sthibault/tags/samuel-thibault' into staging

slirp updates

# gpg: Signature made Sat 27 May 2017 10:36:33 PM BST
# gpg:                using RSA key 0xB0A51BF58C9179C5
# gpg: Good signature from "Samuel Thibault <samuel.thibault@aquilenet.fr>"
# gpg:                 aka "Samuel Thibault <sthibault@debian.org>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@gnu.org>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@inria.fr>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@labri.fr>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@ens-lyon.org>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@u-bordeaux.fr>"
# Primary key fingerprint: 900C B024 B679 31D4 0F82  304B D017 8C76 7D06 9EE6
#      Subkey fingerprint: AEBF 7448 FAB9 453A 4552  390E B0A5 1BF5 8C91 79C5

* sthibault/tags/samuel-thibault:
  Fix total IP header length in forwarded TCP packets
  slirp: fix leak
  slirp: Fix wrong mss bug.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>