In the unit test, check against inet_aton on Linux with GLIBC
only. Other platforms have this function too, but they sometimes have
different behaviour, so don't try to test them equally.
Change-Id: I1a77e405ac7e713d4cf1cee03ea5ce17fb47feef
Reviewed-by: João Abecasis <joao.abecasis@nokia.com>
Reviewed-by: Shane Kearns <shane.kearns@accenture.com>
