GitLab

- make version highlight less blindly greedy and conform to real versions
- move version matching before USE matching to avoid hitting USE flags
  that look like versions
- change USE regex to match the Gentoo PMS
- extend arch match to include more keywords
- make category matching more restrictive to avoid false positives
- drop operators =< and => that Gentoo doesn't support

URL: https://savannah.gnu.org/bugs/?49569

Reported-by: Konstantin Shakhnov <kastian@mail.ru>