* Remove trivial builders.

* Make builders unexecutable by removing the hash-bang line and
  execute permission.
* Convert calls to `derivation' to `mkDerivation'.
* Remove `system' and `stdenv' attributes from calls to
  `mkDerivation'.  These transformations were all done automatically,
  so it is quite possible I broke stuff.
* Put the `mkDerivation' function in stdenv/generic.

svn path=/nixpkgs/trunk/; revision=874

pkgs/development/libraries/mpeg2dec/builder.sh

@@ -1,5 +1,3 @@
-#! /bin/sh
-
 . $stdenv/setup || exit 1
 
 tar xvfz $src || exit 1

pkgs/development/libraries/mpeg2dec/default.nix

@@ -1,10 +1,8 @@
-{stdenv, fetchurl}: derivation {
+{stdenv, fetchurl}: stdenv.mkDerivation {
   name = "mpeg2dec-20030612";
-  system = stdenv.system;
   builder = ./builder.sh;
   src = fetchurl {
     url = http://libmpeg2.sourceforge.net/files/mpeg2dec-0.4.0.tar.gz;
     md5 = "49a70fef1b0f710ed7e64ed32ee82d4d";
   };
-  stdenv = stdenv;
 }