Add script to update curl from upstream

Utilities/Scripts/update-curl.bash

+#!/usr/bin/env bash
+
+set -e
+set -x
+shopt -s dotglob
+
+readonly name="curl"
+readonly ownership="Curl Upstream <curl-library@cool.haxx.se>"
+readonly subtree="Utilities/cmcurl"
+readonly repo="https://github.com/bagder/curl.git"
+readonly tag="curl-7_44_0"
+readonly shortlog=false
+readonly paths="
+  CMake/*
+  CMakeLists.txt
+  COPYING
+  include/curl/*.h
+  include/curl/curlbuild.h.cmake
+  lib/*.c
+  lib/*.h
+  lib/CMakeLists.txt
+  lib/Makefile.inc
+  lib/curl_config.h.cmake
+  lib/libcurl.rc
+  lib/vtls/*.c
+  lib/vtls/*.h
+"
+
+extract_source () {
+    git_archive
+    pushd "${extractdir}/${name}-reduced"
+    rm lib/config-*.h
+    popd
+}
+
+. "${BASH_SOURCE%/*}/update-third-party.bash"