- Update to version 4.3.1

* several important parser fixes
* retire Python v3.5, add v3.9
- Update to version 4.3
* fix recent break due to server-side changes
* option `-e`/`--exclude` to exclude site from results
* option `-g`/`--geoloc` to specify geolocation
* replace uuid1 with uuid4 in request
- Update to version 4.2
* support GUI platform browsers on WSL
* support Wayland native copier `wl-copy`
* program options `--ipv4`, `--ipv6`; ipv4 preferred by default
* deduplicate results
* fix sitelinks parsing
* combine consecutive whitespaces
* fix extraction of matched keywords
* fix match highlighting
* no additional blank line for empty abstracts
* undocumented debug option `--parse` to parse dumped HTML