stays up to date.
* gpgkeys_http.c: Don't need to define HTTP_PROXY_ENV here since it's
in ksutil.h.
* gpgkeys_curl.c (get_key, main), gpgkeys_hkp.c (main): Pass AUTH
values to curl or curl-shim.
* curl-shim.c (curl_easy_perform), gpgkeys_curl.c (main),
gpgkeys_hkp.c (main): Use curl-style proxy semantics.