Enable IPv6 support by default

[suffieldacademy]

This is a feature enhancement request. I am using a device (macOS) that is IPv6-only, and testing Dillo as installed with homebrew. Homebrew uses the default compilation options, which do not include IPv6 (configure.ac requires a flag to enable IPv6, and this is not on by default).

With IPv6 becoming more prevalent (and in Apple's case, mandatory), could you invert the configuration so that IPv6 is enabled by default, and can only be disabled by passing a flag? That would prevent downstream package managers from having to add the flag to each of their build scripts.

If IPv6 support is not fully tested or ready for default deployment, then I completely understand and I can build my own manually with support enabled.