jsoncpp: Add script to update from upstream

Utilities/Scripts/update-jsoncpp.bash

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+
+set -e
+set -x
+shopt -s dotglob
+
+readonly name="jsoncpp"
+readonly ownership="JsonCpp Upstream <kwrobot@kitware.com>"
+readonly subtree="Utilities/cmjsoncpp"
+readonly repo="https://github.com/open-source-parsers/jsoncpp.git"
+readonly tag="1.0.0"
+readonly shortlog=false
+readonly paths="
+  LICENSE
+  include/json
+  src/lib_json
+"
+readonly remove="
+  include/json/autolink.h
+  src/lib_json/CMakeLists.txt
+  src/lib_json/sconscript
+  src/lib_json/version.h.in
+"
+
+extract_source () {
+    git_archive
+    pushd "${extractdir}/${name}-reduced"
+    rm $remove
+    echo "* -whitespace" > .gitattributes
+    popd
+}
+
+. "${BASH_SOURCE%/*}/update-third-party.bash"