This includes three fixes:

a) nfcache bits are reset once the events has been delivered. Loopback 
connections events are notified twice.

b) Don't kill NFC_IP_*. Just more it into a #ifndef __KERNEL__ fence, 
that way we don't break iptables backward compilation.

c) IPCT_DESTROY is delivered from destroy_conntrack. Some users has 
reported out of logical order event notification. This fixes the problem.