gai_strerror(3) on FreeBSD

The text f28024fe4cbf, as FreeBSD 6.3-RELEASE, FreeBSD 6.2-RELEASE, FreeBSD 6.1-RELEASE, FreeBSD 6.0-RELEASE shipped it.

get error message string from EAI_xxx error code

gai_strerror(3) on FreeBSD now