Fix issue where context menu wouldn't come back after dragging

Update scratch-l10n to the latest version 

Update paint

Fix saving after recording a sound

Update scratch-blocks to the latest version 

Add play buttons to sound library tiles for touch

Make delete button accessible

Add Jest-specific linting rules

Adding this caught a couple of important things:
- The sound integration tests have a `.only` in them
- The project-saver-hoc tests had two tests with the same description, causing possible confusion if that test broke

Also noticed that Delete aria label was not localized.

Update scratch-l10n to the latest version 

Use the classNames feature to include/exclude a class based on a boolean instead of ternary operator

* split play-button into container and component
* revised sound library tile:
  * play button in upper right
  * smaller sound icon (make the tile less loaded)

Play button doesn’t have a ‘touch-outside’ listener to stop sounds. That seems to be ok as other events cause the sound to stop.

Both handleClick and handleMouseDown are needed. Must use handleMouseDown for `preventDefault` to skip setting focus on the item. handleClick is needed to prevent the Click from propagating to the item and selecting it.

Update UI play/stop button when the sound ends

Play button is larger (easier to touch). Can both start and stop sounds.
Sound doesn’t restart on mouseEnter if the sound is already playing.
Sound stops if you move off play button

Missing: stop button does not revert to play button when the sound finishes.

Checked with Carl and updated the style of the play button.

Add prop to library items to show a play button. If a play button is present the ‘play on hover’ only applies over the icon rather than the full tile.

Update scratch-vm to the latest version 

Update scratch-vm to the latest version 

Remove test.only

Update chromedriver to the latest version 

Greenkeeper/scratch blocks 0.1.0 prerelease.1564581595

Update fade icons

Prevent default when dragging trim handles to prevent image drag