iniparser: add pkgconfig file

The upstream pkgconfig file is not contained in any release, add our own
based on it.

pkgs/development/libraries/iniparser/default.nix

@@ -36,6 +36,9 @@ stdenv.mkDerivation rec {
     cp libiniparser.a $out/lib
     cp libiniparser.so.1 $out/lib
     ln -s libiniparser.so.1 $out/lib/libiniparser.so
+
+    mkdir -p $out/lib/pkgconfig
+    substituteAll ${./iniparser.pc.in} $out/lib/pkgconfig/iniparser.pc
   '';
 
   meta = with lib; {

pkgs/development/libraries/iniparser/iniparser.pc.in

@@ -0,0 +1,12 @@
+prefix=@out@
+exec_prefix=@out@
+libdir=${exec_prefix}/lib
+includedir=${prefix}/include
+datarootdir=${prefix}/share
+datadir=${datarootdir}
+
+Name: libiniparser
+Description: Iniparser library
+Version: @version@
+Libs: -L${libdir} -liniparser
+Cflags: -I${includedir}