add .gitignore and .travis.yml
ping_common.c: fix typo

Debian bug #698287
Only emit an audible ping when requested (including flooding).

The changeset 59de58d0f92a2c9b90174e51070aca32e7959e28
"iputils-s20100214" changed flooding to always make an audible ping
when flooding, but didn't provide anyway to disable the audible ping
when flooding.  That's a problem when you want to see the results of
the flood ping, but not hear it.  This patch changes the behavior to
match the normal ping case, no audible ping by default, and -a enables
the ping.

Signed-off-by: David Fries <david@fries.net>
Disable DNS-lookup on every ping

The ip lookups that are done for every received icmp packet can lead to
very confusing results if DNS is fubarred (for example, if one dns
server is down, so every dns lookup involves a timeout on that server).

Debian bug: #109709
tracepath: return correct number of hops

Debian bug: #629075
arping: return immediately

Debian bug: #686944
ping: flush stdout when a truncated response is received

Debian bug: #628893
replace gethostbyname with gethostbyname2

Debian bug: #305062
remove bogus check required for < 2.4.9 kernels

Debian bug: #709052