vlan v2

Fix crash: https://redmine.openinfosecfoundation.org/issues/1120
Fix vlan id's in wrong byte order in eve-log.

Prscript:
- PR build: https://buildbot.suricata-ids.org/builders/inliniac/builds/216
- PR pcaps: https://buildbot.suricata-ids.org/builders/inliniac-pcap/builds/136