Closes #4540

Update scratch-vm to the latest version 

Delete Preview Modal

Update scratch-l10n to the latest version 

Gif upload v1: sprites, costumes

Tag NPM releases

Check if an NPM release just happened. And if so, tag the commit and push to GitHub.

Thanks to @paulkaplan for pairing on this

Update scratch-blocks to the latest version 

Remove prune step from deployment for now

Update scratch-l10n to the latest version 

Sort variable options in "of" block

It doesn't affect greenkeeper subdirectories, which are the ones that cause the most issues. And now the prune step itself is breaking builds. So until it works better, remove this step.

require text-encoding only if it is needed

Set an initial message number to skip rendering a second time

chore(package): update scratch-vm to version 0.2.0-prerelease.2019020…

chore(package): update scratch-render to version 0.1.0-prerelease.201…

Closes #4513

Multiple file upload for costumes, sounds, backdrops and sprites

Closes #4510

Merge pull request #4512 from LLK/revert-4501-greenkeeper/scratch-render-0.1.0-prerelease.20190206213754

Revert "Update scratch-render to the latest version "

chore(package): update scratch-vm to version 0.2.0-prerelease.2019020…

Closes #4506