* common/http.c (send_request, connect_server, http_open): Use a
struct srv instead of a single srvtag so we can pass the chosen host
and port back to the caller.
(connect_server): Use the proper port in the HAVE_GETADDRINFO case.
* keyserver/curl-shim.c (curl_easy_perform): Use struct srv and log
chosen host and port.
* keyserver/gpgkeys_hkp.c (main): Properly take the port given by SRV.
sufficient to turn the feature on. (http_open): From here.
(http_document): And here.
* gpgkeys_hkp.c (srv_replace): New function to transform a SRV
hostname to a real hostname. (main): Call it from here for the
HAVE_LIBCURL case (without libcurl is handled via the curl-shim).
* curl-shim.h, curl-shim.c (curl_easy_setopt, curl_easy_perform): Add
a CURLOPT_SRVTAG_GPG_HACK (passed through the the http engine).
