WebP - embedded Versions

[kbachl]

Since google already released 1.3.0 of their WebP libraries the embedded ones should be upgraded (https://storage.googleapis.com/downloads.webmproject.org/releases/webp/index.html).
Also it would be good to have a "versions.txt" file in the scrimage/scrimage-webp/src/main/resources/dist_webp_binaries/DIST/ folders so the version can be seen.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[sharmando]

bump

[sksamuel]

I've updated them and made the directory structure much clearer so it's obvious which versions are included.
Will release shortly.