misc: use ipv4 as option rather than family Now, all sections and JSON options that require a IP family will take ipv4 and ipv6 boolean options for convenience. It reduces parsing complexity and is more convenient for the user. Examples: # IPv6 server only [server] name = example port = 6667 hostname = example.org ipv4 = false ipv6 = true # IPv4 transport only [transport] type = ip ipv4 = true ipv6 = false port = 3320 If both options are defined (default everywhere), both protocols will be tried or bound.