Updating giv to latest from git (>0.9.25).

We were using a version years old.

I picked the git version instead of the last release because the git version
has fixes not released for almost one year.

pkgs/applications/graphics/giv/build.patch

@@ -15,30 +15,3 @@ index 16eccd9..603e931 100644
  
  env['SBOX'] = False
  
-diff --git a/giv/SConstruct b/giv/SConstruct
-index 047839a..2c267aa 100644
---- a/giv/SConstruct
-+++ b/giv/SConstruct
-@@ -3,8 +3,9 @@
- 
- import sys
- import re
-+import os
- 
--env = Environment()
-+env = Environment(ENV = os.environ)
- 
- src = ["giv.c",
-        "giv-backstore.c",
-diff --git a/src/plugins/dcmtk/SConstruct.standalone b/src/plugins/dcmtk/SConstruct.standalone
-index ffce001..74246f8 100644
---- a/src/plugins/dcmtk/SConstruct.standalone
-+++ b/src/plugins/dcmtk/SConstruct.standalone
-@@ -1,4 +1,6 @@
--env = Environment()
-+import os
-+
-+env = Environment(ENV = os.environ)
- 
- variant = "Debug"
- 

pkgs/applications/graphics/giv/default.nix

@@ -1,12 +1,14 @@
-{ stdenv, fetchurl, gdk_pixbuf, scons, pkgconfig, gtk, glib,
+{ stdenv, fetchFromGitHub, gdk_pixbuf, scons, pkgconfig, gtk, glib,
   pcre, cfitsio, perl, gob2, vala, libtiff, json_glib }:
 
 stdenv.mkDerivation rec {
-  name = "giv-0.9.22";
+  name = "giv-20150811-git";
 
-  src = fetchurl {
-    url = "mirror://sourceforge/giv/${name}.tar.gz";
-    sha256 = "1q0806b66ajppxbv1i71wx5d3ydc1h3hsz23m6g4g80dhiai7dly";
+  src = fetchFromGitHub {
+    owner = "dov";
+    repo = "giv";
+    rev = "64648bfbbf10ec4a9adfbc939c96c7d1dbdce57a";
+    sha256 = "1sz2n7jbmg3g97bs613xxjpzqbsl5rvpg6v7g3x3ycyd35r8vsfp";
   };
 
   # It built code to be put in a shared object without -fPIC