add udunits: a C library for units of physical quantities

pkgs/development/libraries/udunits/configure.patch

@@ -0,0 +1,12 @@
+diff -ru -x '*~' udunits-2.1.24_orig/configure udunits-2.1.24/configure
+--- udunits-2.1.24_orig/configure	2011-09-13 05:58:39.000000000 +0900
++++ udunits-2.1.24/configure	2014-11-21 21:59:30.308180814 +0900
+@@ -7033,7 +7033,7 @@
+   ac_status=$?
+   $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
+   (exit $ac_status); }; then
+-    case `/usr/bin/file conftest.o` in
++    case `$MAGIC_CMD conftest.o` in
+     *32-bit*)
+       case $host in
+         x86_64-*kfreebsd*-gnu)

pkgs/development/libraries/udunits/default.nix

@@ -0,0 +1,19 @@
+{ stdenv, fetchurl,
+  bison, flex, expat, file
+}:
+
+stdenv.mkDerivation rec {
+    name = "udunits-2.1.24";
+    src = fetchurl {
+        url = "ftp://ftp.unidata.ucar.edu/pub/udunits/${name}.tar.gz";
+        sha256 = "1l0fdsl55374w7fjyd1wdx474f3p265b6rw1lq269cii61ca8prf";
+    };
+
+    buildInputs = [
+        bison flex expat file
+    ];
+
+    patches = [ ./configure.patch ];
+
+    MAGIC_CMD="${file}/bin/file";
+}

pkgs/top-level/all-packages.nix

@@ -2671,6 +2671,8 @@ let
 
   ttmkfdir = callPackage ../tools/misc/ttmkfdir { };
 
+  udunits = callPackage ../development/libraries/udunits { };
+
   uim = callPackage ../tools/inputmethods/uim {
     inherit (pkgs.kde4) kdelibs;
   };