fdk-aac: refactor and add example optional

pkgs/development/libraries/fdk-aac/default.nix

@@ -1,19 +1,25 @@
-{ stdenv, fetchurl }:
+{ stdenv, fetchurl
+, exampleSupport ? true # Example encoding program
+}:
 
-let version = "0.1.3";
-in
-stdenv.mkDerivation {
+with stdenv.lib;
+stdenv.mkDerivation rec {
   name = "fdk-aac-${version}";
+  version = "0.1.3";
 
   src = fetchurl {
-    url = "mirror://sourceforge/opencore-amr/fdk-aac/fdk-aac-${version}.tar.gz";
+    url = "mirror://sourceforge/opencore-amr/fdk-aac/${name}.tar.gz";
     sha256 = "138c1l6c571289czihk0vlcfbla7qlac2jd5yyps5dyg08l8gjx9";
   };
 
-  meta = with stdenv.lib; {
+  configureFlags = [ ]
+    ++ optional exampleSupport "--enable-example";
+
+  meta = {
     description = "A high-quality implementation of the AAC codec from Android";
-    homepage = "http://sourceforge.net/projects/opencore-amr/";
-    license = licenses.asl20;
-    platforms = platforms.linux;
+    homepage    = http://sourceforge.net/projects/opencore-amr/;
+    license     = licenses.asl20;
+    maintainers = with maintainers; [ codyopel ];
+    platforms   = platforms.all;
   };
 }