It has been default for a while, is the only tested option,
and will only get more common.
It's not enabled anywhere, certainly not maintained
- Removes need to check for malloc failure
- Removes need for NULL checks on free
- Adds checks for integer overflows
- Removes some extra memset calls
- Removes chance of mixing libc and glib malloc/free
AI_ADDRCONFIG helps not to try to connect unreachable ipv6 address if
user doesn't have ipv6 network stack.