git-imerge: new package

pkgs/applications/version-management/git-and-tools/default.nix

···
   git-extras = callPackage ./git-extras { };
 
   git-cola = callPackage ./git-cola { };
+
+  git-imerge = callPackage ./git-imerge { };
 }

pkgs/applications/version-management/git-and-tools/git-imerge/default.nix

···
+{ stdenv, fetchurl, pythonPackages }:
+
+stdenv.mkDerivation rec {
+  name = "git-imerge-${version}";
+  version = "0.7.0";
+
+  src = fetchurl {
+    url = "https://github.com/mhagger/git-imerge/archive/${version}.tar.gz";
+    sha256 = "00nwn3rfhf15wsv01lfji5412d7yz827ric916lnyp662d6gx206";
+  };
+
+  buildInputs = [ pythonPackages.python pythonPackages.wrapPython ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    make install PREFIX=$out
+    wrapPythonPrograms
+  '';
+
+  meta = with stdenv.lib; {
+    homepage = https://github.com/mhagger/git-imerge;
+    description = "Perform a merge between two branches incrementally";
+    license = licenses.gpl2;
+    platforms = platforms.all;
+    maintainers = [ maintainers.spwhitt ];
+  };
+}