Merge IPv4 and IPv6 support into net/fping, selectable via options.
Remove the now un-needed net/fping+ipv6
Add common description for IPV4 option, analogous to the IPV6 option
PR: ports/169949 [1], ports/169950 [2]
Submitted by: Rodrigo OSORIO <rodrigo@bebik.net> [1]
Jason Harris <jharris@widomaker.com> [2]
zeising (final patch version)
Approved by: maintainer, kwm (mentor)