Пакет alterator-net-functions: Информация

- Re-build for the C7 branch.

- Added is_ipv6_enabled() function.

- refdns: Replace valid_ipv4() with valid_ipv4addr().
- Added valid_ipv4addr() function.
- Added tests for ipv6addr_is_in_subnet() function.
- Added get_ip_version() function.
- revdns: Added IPv6 support.
- Added ipv6addr_is_in_subnet() function.
- ipv6_network(): Use valid_ipv6prefix().
- Added valid_ipv6prefix() and valid_ipv4prefix() functions.