General:
- internal databases: update
IP2Location 8.7.0 related (relates to https://github.com/chrislim2888/IP2Location-C-Library/releases/tag/8.7.0 which has unfortunatly incompatible API changes)
- ipv6calcweb/ipv6calcweb.cgi.in: add support for new fields in DB26 with 8.7.0
- add support for additional data in DB26 usable with IP2Location >= 8.7.0
- check IP2Location > 8.6.1 related compatibility/fallback
Extensions:
- add option
--has-feature <NAME>