expanding iprep support v0.2

This addresses the problem found in the last PR, in some situation packets are not matched.

Feature [#707](https://redmine.openinfosecfoundation.org/issues/707)
Last PR https://github.com/inliniac/suricata/pull/1152

- PR build: https://buildbot.openinfosecfoundation.org/builders/glongo/builds/8
- PR pcaps: https://buildbot.openinfosecfoundation.org/builders/glongo-pcap/builds/8

Since we're now building 120 trees (60 cats for both ipv4 and ipv6), I think we waste a lot of memory this way.

We should probably initialize the trees on-demand, so only if we add rep data to a cat, init the tree.