curl: split into multiple outputs

Also use pkgconfig to be safer and fix (some) referrers.

pkgs/development/interpreters/elixir/default.nix

@@ -30,7 +30,7 @@ stdenv.mkDerivation {
      b=$(basename $f)
       if [ $b == "mix" ]; then continue; fi
       wrapProgram $f \
-        --prefix PATH ":" "${erlang}/bin:${coreutils}/bin:${curl}/bin:${bash}/bin" \
+        --prefix PATH ":" "${erlang}/bin:${coreutils}/bin:${curl.bin}/bin:${bash}/bin" \
         --set CURL_CA_BUNDLE /etc/ssl/certs/ca-certificates.crt
     done