bsdiff: adopt and clean up

Bonus: simpler build, and should fix the build of bsdiff for Darwin
(patch taken from homebrew).

Signed-off-by: Austin Seipp <aseipp@pobox.com>

pkgs/tools/compression/bsdiff/default.nix

@@ -1,14 +1,37 @@
-{stdenv, fetchurl, bzip2}:
+{ stdenv, fetchurl, bzip2 }:
+
+stdenv.mkDerivation rec {
+  name    = "bsdiff-${version}";
+  version = "4.3";
 
-stdenv.mkDerivation {
-  name = "bsdiff-4.3";
-  builder = ./builder.sh;
   src = fetchurl {
-    url = http://www.daemonology.net/bsdiff/bsdiff-4.3.tar.gz;
+    url    = "http://www.daemonology.net/bsdiff/${name}.tar.gz";
     sha256 = "0j2zm3z271x5aw63mwhr3vymzn45p2vvrlrpm9cz2nywna41b0hq";
   };
+
   buildInputs = [ bzip2 ];
-  patchPhase = ''
-    sed 's/^\.//g' -i Makefile
+  patches = [ ./include-systypes.patch ];
+
+  buildPhase = ''
+    cc -O3 -lbz2 bspatch.c -o bspatch
+    cc -O3 -lbz2 bsdiff.c  -o bsdiff
   '';
+
+  installPhase = ''
+    mkdir -p $out/bin
+    mkdir -p $out/share/man/man1
+
+    cp bsdiff    $out/bin
+    cp bspatch   $out/bin
+    cp bsdiff.1  $out/share/man/man1
+    cp bspatch.1 $out/share/man/man1
+  '';
+
+  meta = {
+    description = "An efficient binary diff/patch tool";
+    homepage    = "http://www.daemonology.net/bsdiff";
+    license     = stdenv.lib.licenses.bsd2;
+    platforms   = stdenv.lib.platforms.unix;
+    maintainers = [ stdenv.lib.maintainers.thoughtpolice ];
+  };
 }