- Grow sfIpAddress to hold IPv6 addresses and add address types
- Make sfIpAddress_fromString not resolve network names anymore, matching sf::IpAddress::fromString, and add the deprecated sfIpAddress_resolve
- Add sfDns for resolving hostnames and querying NS, MX, SRV and TXT records
On some PCs, resolving `invalid address` will perform a real name
resolution using the network. This is slows down the test and risks
the test failing if the resolution succeeds.
Use `localhost` instead which shold return a known value, and add an
invalid ip address test for good measure.
Lukas Dürrenberger