* configure.ac: Cehck for inet_ntop.
* m4/libcurl.m4: Provide a #define for the version of the curl
library.
--
We do not have keyserver helpers anymore but this fixes may come handy
eventually.
* m4/libcurl.m4: Do not use AC_PATH_PROG if --with-libcurl as been
given. Suggested by John Marshall.
--
GnuPG-bug-id: 1510
(cherry picked from commit 110b52fffa)