Log Message:
Changes 4.0:

Incompatible Changes
- fping and fping6 unification
- Option -n, not the same as -d anymore
- Discarding of late packets
- No restrictions by default
- Default interval (-i) changed from 25ms to 10ms

New features
- Unified 'fping' and 'fping6' into one binary
- Long option names for all options
- IPv6 enabled by default
- New option -4 to force IPv4
- New option -6 to force IPv6
- Keep original name if a hostname is given with -n/--name
- Option -d/--rdns now always does a rdns-lookup, even for names, as '-n' was \ 
doing until now
- Enforce -t timeout on reply packets, by discarding late packets
- Auto-adjust timeout for -c/-C/-l mode to value of -p

Bugfixes and other changes
- -i/-p restrictions disabled by default (enable with --enable-safe-limits)
- Default interval -i changed from 25ms to 10ms
- Fix compatibility issue with GNU Hurd
- A C99 compiler is now required
- Option parsing with optparse (https://github.com/skeeto/optparse)
- New changelog file format