bzip2: add script to import bzip2 from upstream

Utilities/Scripts/update-bzip2.bash

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+set -e
+set -x
+shopt -s dotglob
+
+readonly name="bzip2"
+readonly ownership="bzip2 upstream <kwrobot@kitware.com>"
+readonly subtree="Utilities/cmbzip2"
+readonly repo="https://sourceware.org/git/bzip2.git"
+readonly tag="bzip2-1.0.5"
+readonly shortlog=false
+readonly paths="
+  LICENSE
+  README
+  *.c
+  *.h
+"
+
+extract_source () {
+    git_archive
+    pushd "${extractdir}/${name}-reduced"
+    echo "* -whitespace" > .gitattributes
+    popd
+}
+
+. "${BASH_SOURCE%/*}/update-third-party.bash"