Now, the filter uses B-trees for exact string matching and Aho-Corasick
machines for substring matching. B-trees and AC machines are exported to
linked lists for debug logging only.
Also,
- Separate all_sites and all_ports filters from substring filters. They
are not related with substring filters actually, and ACM keywords cannot
be empty strings anyway. So now they should be handled separately too.
- Improve debug logging of filtering rules.
- Update unit tests accordingly, and improve.
- Fix pxyconn_filter(), keep searching for a match in substring filters
if exact match does not have a matching site rule.
- Increase common names max len and tokens. weather.gov has 73 tokens.
- Rename keyword to desc.
- Update documentation.
- Clean up.