resolves bottleneck by initial scanning of a lot of messages (or evildoers generating many messages) causes repeated ban, that will be ignored but could cause entering of "long" sleep in actions thread previously;
speedup recognition banning queue has entries to begin check-ban process in actions thread
amend to 62b1712d22 (PR #2387, backend-related option `logtype`);
testSampleRegexsZZZ-GENERIC-EXAMPLE covering now negative case also (other daemon in prefix line)
datetemplate: improved anchor detection for capturing groups `(^...)`; introduced new prefix `{UNB}` for `datepattern` to disable word boundaries in regex;
datedetector: speedup special case if only one template is defined (every match wins - no collision, no sorting, no other best match possible)
- avoid duplicates in "matches" (previously always added matches of pending failures to every next real failure, or nofail-helper recognized IP, now first failure only);
- several optimizations of merge mechanism (multi-line parsing);
fail2ban-regex: better output handling, extended with tag substitution (ex.: `-o 'fail <ip>, user <F-USER>: <msg>'`); consider a string containing new-line as multi-line log-excerpt (not as a single log-line)
filter.d/sshd.conf: introduced parameter `publickey` (allowing change behavior of "Failed publickey" failures):
- `nofail` (default) - consider failed publickey (legitimate users) as no failure (helper to get IP and user-name only)
- `invalid` - consider failed publickey for invalid users only;
- `any` - consider failed publickey for valid users too;
- `ignore` - ignore "Failed publickey ..." failures (don't consider failed publickey at all)
tests/samplestestcase.py: SampleRegexsFactory gets new failJSON option `constraint` to allow ignore of some tests depending on filter name, options and test parameters
avoid overwrite of data with empty tags by ticket constructed from multi-line failures;
amend to d1b7e2b5fb2b389d04845369d7d29db65425dcf2: better output (as well as ignoring of pending lines) using `--out msg`;
filter.d/sshd.conf: don't forget mlf-cache on "disconnecting: too many authentication failures" - message does not have IP (must be followed by "closed [preauth]" to obtain host-IP).
implements new command line option `--pname` to specify it by start of server (default `fail2ban-server`);
closes gh-2623 (revert change of main thread-name, because it can affect process-name too, so `pgrep` & co. may be confused)
Sergey G. Brester