Ultrastar (#26524)

* ultrastardx-beta: init at 1.3.5

* libbass, libbass_fx: init at 24

* ultrastar-creator: init at 2017-04-12

* buildSupport/plugins.nix: add diffPlugins

Helper function to compare expected plugin lists to the found plugins.

* ultrastar-manager: init at 2017-05-24

The plugins are built in their own derivations, speeding up (re-)compilation.
The `diffPlugins` function from `beets` is reused to test for changes in the
plugin list on updates.

* beets: switch to diffPlugins

The function is basically just extracted for better reusability.

pkgs/development/libraries/audio/libbass/default.nix

@@ -0,0 +1,59 @@
+{ stdenv, unzip, fetchurl, writeText }:
+
+let
+  version = "24";
+
+  allBass = {
+    bass = {
+      h = "bass.h";
+      so = {
+        i686_linux = "libbass.so";
+        x86_64-linux = "x64/libbass.so";
+      };
+      urlpath = "bass${version}-linux.zip";
+      sha256 = "1a2z9isabkymz7qmkgklbjpj2wxkvv1cngfp9aj0c9178v97pjd7";
+    };
+
+    bass_fx = {
+      h = "C/bass_fx.h";
+      so = {
+        i686_linux = "libbass_fx.so";
+        x86_64-linux = "x64/libbass_fx.so";
+      };
+      urlpath = "z/0/bass_fx${version}-linux.zip";
+      sha256 = "0j1cbq88j3vnqf2bibcqnfhciz904w48ldgycyh9d8954hwyg22m";
+    };
+  };
+
+  dropBass = name: bass: stdenv.mkDerivation {
+    name = "lib${name}-${version}";
+
+    src = fetchurl {
+      url = "https://www.un4seen.com/files/${bass.urlpath}";
+      inherit (bass) sha256;
+    };
+    unpackCmd = ''
+      mkdir out
+      ${unzip}/bin/unzip $curSrc -d out
+    '';
+
+    lpropagatedBuildInputs = [ unzip ];
+    dontBuild = true;
+    installPhase =
+      let so =
+            if bass.so ? ${stdenv.system} then bass.so.${stdenv.system}
+            else abort "${name} not packaged for ${stdenv.system} (yet).";
+      in ''
+        mkdir -p $out/{lib,include}
+        install -m644 -t $out/lib/ ${so}
+        install -m644 -t $out/include/ ${bass.h}
+      '';
+
+    meta = with stdenv.lib; {
+      description = "Shareware audio library";
+      homepage = https://www.un4seen.com/;
+      license = licenses.unfreeRedistributable;
+    };
+  };
+
+in stdenv.lib.mapAttrs dropBass allBass