Unix socket enhanced v1.2

Here's a patchset which bring some big improvements to unix socket. A bunch of new commands have been add: "command-list", "help", "version", "uptime", "running-mode",     "capture-mode", "conf-get" and "dump-counters".
suricatasc has been reworked to be a module (usable in other projects) and a script. It is now featuring completion.
All change are read-only with the only command with significant code being "dump-counters".