* 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/libpng/builder.sh

@@ -1,5 +1,3 @@
-#! /bin/sh -e
-
 buildInputs="$zlib"
 . $stdenv/setup
 

pkgs/development/libraries/libpng/default.nix

@@ -2,14 +2,12 @@
 
 assert zlib != null;
 
-derivation {
+stdenv.mkDerivation {
   name = "libpng-1.2.5";
-  system = stdenv.system;
   builder = ./builder.sh;
   src = fetchurl {
     url = http://heanet.dl.sourceforge.net/sourceforge/png-mng/libpng-1.2.5.tar.bz2;
     md5 = "3fc28af730f12ace49b14568de4ad934";
   };
-  stdenv = stdenv;
   zlib = zlib;
 }