pfring: implements ips mode

This PR permits to use suricata and PF_RING in ips mode.

Configuration for using PF_RING in IPS mode:
pfring:
- interface: p4p1
threads: 1
cluster-id: 99
cluster-type: cluster_flow
copy-mode: ips
copy-iface: eth1
flow-packet: yes
# Second interface
- interface: eth1
threads: 1
cluster-id: 99
cluster-type: cluster_flow
copy-mode: ips
copy-iface: p4p1
flow-packet: yes

- PR build: https://buildbot.openinfosecfoundation.org/builders/glongo/builds/19
- PR pcaps: https://buildbot.openinfosecfoundation.org/builders/glongo-pcap/builds/18