PORT
Provide better error messages to allow debugging if one if the ipv6-related
name functions fail in the ftp_use_port() function. This might help us
diagnose the problems on AIX. Also make sure getaddrinfo() uses NULL and
not "0" for the service argument.

response reading function

NOTE that this breaks ares-compatibility, we have now officially taken the
turn into the c-ares path. We will now officially depend on c-ares for asynch
name resolves.

as well, and when failing and not getting a timeout we now include the
error message ares can provide us with.

this allows the HTTP code to *not* return a failure just because no data
has been received from the server

Dirk Manske, but modified by me.

the search path since we want the build-version rather than the one in the
source dir

so that the automatic testing hosts will test these changes over the weekend.

2. now reads the socket error before check connect status, also to make us
   run fine on MPE/iX

warnings. Minor edits by me.

sequence.

been transfered!

to make it easier to track down

messed up. Vincent Bronner detected this.

be NULL pointers, and if non-NULL if now support zero-length names/passwords

The initial QUIT-sending code is added, but not yet used due to the issues
previously mentioned on the mailing list.