Dev log api v2.3

Changes since https://github.com/inliniac/suricata/pull/769:
- convert prelude
- convert pcap-info
- convert syslog

Prscript:
- PR build: https://buildbot.suricata-ids.org/builders/inliniac/builds/138                                                                                                                                                    
- PR pcaps: https://buildbot.suricata-ids.org/builders/inliniac-pcap/builds/58