Files are created as root, user _suricata cannot open them. Use
filemode 664 in the default config where possible. Use syslog for
general logging. Fix possible NULL dereference found by Emmanuel
Roullit.
OK sthen@ gonzalo@
Suricata uses libcap-ng on Linux and runs as root elsewhere.
Switch to _suricata user and group in config to avoid running as root.
To remove pid file its directory must be writable by suricata user.
Fix pid file removal if it is specified in config file.
setresuid()/gid() patch from Emmanuel Roullit
OK gonzalo@
