pcapparse: add support for IPv6

Submitted by Felipe Alexandre Ferreira

Link to original bug (#735991)

Description

Created attachment 285288
Changes to add support for IPv6 and IP in IP tunneling

pcapparse bad plugin don't support IPv6 packages, just IPv4. I made a patch to add IPv6 support, and tunneling 6in4 or 4in6.
I've made the patch based in 0.10 branch, but since the code of function that decodes IP header don't changed, i think it will work in 1.x branches.

Patch 285288, "Changes to add support for IPv6 and IP in IP tunneling":
pcapparse.patch