new animated-screenshots

- half size: 1465 KB -> 641KB
- mutch better quality
- no MakeAGIF.com branding
- HTTPS link (via github gist) so there is no github-camo proxy needed (camo makes this image loading 0.55s slower in my short test)
- all source-files are available here: https://gist.github.com/fnkr/2f9badd56bfe0ed04ee7
changed the image link to include the commit SHA
Merge pull request #4738 from fnkr/patch-1

new animated-screenshots