Patch CVE-2021-28021, CVE-2021-42715, and CVE-2021-42716
- Backport 8f9bb9563980b41e7695148b63bf09f7abd38a41 from upstream dev
branch to update bundled stb libraries
- Use the included patch files on externally-packaged copies to create
forked versions that contain fixes for the mentioned CVEs (unbundles
stb_image, stb_image_write)