rl_catch_signals.
* libcurl.m4: Don't require curl-config to be present since it seems some
binary packages don't include it. Allow users to specify LIBCURL and
LIBCURL_INCLUDES for us.
(min_automake_version): New.
* LINGUAS: Added all languages we supported in 1.2.5.
Copied all po files from 1.2.5.
* autogen.sh: Updated to the modern version, grepping the required
tool versions from configure.ac.