Idstools

- idstools-rulecat: fix issue parsing Suricata version on Python 3
- idstools-rulecat: don't convert rules with noalert to drop
- idstools-rulecat: allow suricata version to be set on the command
line (https://github.com/jasonish/py-idstools/issues/38)

[Full commit log.](https://github.com/jasonish/py-idstools/compare/0.5.5...0.5.6)

Changes:
- unified2: fix reading of ipv6 events
- idstools-u2json: option to sort the keys
- u2spewfoo: IPv6 printing fixes
- idstools-rulecat: use ET "enhanced" rules by default
- idstools-rulecat: suricata inspired colour logging
- idstools-rulecat: handle URLs ending with query parameters

- idstools: handle rules with no msg in rule parser
- idstools-rulecat: support a drop.conf for setting rules to drop
- idstools-eve2pcap: allow link type to be set on command line
- unified2: handle large appid buffer in newer versions of Snort.

- idstools-rulecat: better documentation
- idstools-rulecat: use ET Pro https URL

- idstools-u2json: fix --delete
- idstools-u2json: add --verbose flag for debug logging
- idstools-rulecat: allow multiple urls

- New tool: eve2pcap. Converts packets and payloads found in Suricata
EVE logs to pcap files.
- Rule parser: handle multi-line rules.