Remove jing_tools expression (now contained in jing expression itself)

The jing expression now creates its own "jing" wrapper script, so there
is no need for jing_tools anymore.

jing hasn't been updated in years, so I assume (or hope) that not many
(if any) have jing_tools in their configuration.nix. If you do, just
change it to jing and it should behave the same.

pkgs/tools/text/xml/jing/jing-script.nix

@@ -1,12 +0,0 @@
-{stdenv, fetchurl, jre, unzip} :
-
-stdenv.mkDerivation {
-  name = "jing-tools-20030619";
-  builder = ./script-builder.sh;
-
-  jing = (import ./default.nix) {
-    inherit stdenv fetchurl unzip;
-  };
-
-  inherit jre;
-}

pkgs/tools/text/xml/jing/script-builder.sh

@@ -1,14 +0,0 @@
-source $stdenv/setup
-
-mkdir -p $out/bin
-
-cat >> $out/bin/jing <<EOF
-#! $SHELL
-
-export JAVA_HOME=$jre
-export LANG="en_US"
-
-exec $jre/bin/java -jar $jing/bin/jing.jar "\$@"
-EOF
-
-chmod a+x $out/bin/jing