Fixed Hackfest compatibility and pushed net/ commits

tproxy: added IPv6 socket lookup function to nf_tproxy_core
tproxy: added udp6_lib_lookup function
compat_ioctl: add compat handler for TIOCGSID ioctl
CacheFiles: Fix a race in cachefiles_delete_object() vs rename
tproxy: split off ipv6 defragmentation to a separate module
Fixed hackfest compatibility (2/2)