From a functional point of view, the main improvement is that GetIP() now always prioritizes IPv6 over IPv4.
The previous implementation always returned an IPv4 address, unless not available: in such case it failed.
This means that now connections to hostnames should be established via IPv6 if available.
From a programmer point of view, getting rid of the insane wrappers is enough to justify a complete rewrite.
As an extra, several unrelated unused global variables are removed.
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