* refactor LanguageSelector to reuse MenuBarMenu
* localize aria-labels on MenuBar

Allows the language selection menu to be active if `?enable=language` is in the URL, otherwise shows a ‘coming soon’ tooltip. This can also land on a branch if we don’t want that available on preview.

- language menu opens if the globe is clicked
- language menu closes if mouse is clicked anywhere outside the language selector
- language list is imported from scratch-l10n
- current locale is updated if another language is selected (i.e. the current language selected changes)

Not in this PR:
- styling of language selector
- actually changing the messages!

Update scratch-blocks to the latest version 

Update scratch-blocks to the latest version 

chore(package): update scratch-l10n to version 3.0.20180611175036

Update scratch-audio to the latest version 

Update scratch-storage to the latest version 

Closes #2313

Update scratch-paint to the latest version 

Update scratch-blocks to the latest version 

Prevent pushing tutorial cards beyond width

Move z-index values to separate file

Update chromedriver to the latest version 

Fix "Opening the backdrop library causes the stage backdrop editor to become selected"

Fix sprite selector scroll bar

Change CSS

Update scratch-blocks to the latest version 

Update classnames to the latest version 

Update scratch-paint to the latest version 

Merge smoke changes for 6/8/18 iteration to back into develop

Revert "Add when touching hat"

This reverts commit 94915a9a.

Add when touching hat