Remove the WebGL checks from the error boundary. Instead, just do not
render the stage if it is not supported.

Update scratch-blocks to the latest version 

Merge pull request #1232 from LLK/greenkeeper/scratch-vm-0.1.0-prerelease.1515691021-prerelease.1515691035

Update scratch-vm to the latest version 

Exit full-screen mode by hitting escape key

Set default input width

Get GUI working on Edge

Clean up monitor dropdown strings

* Added object.assign polyfill

* Fix IE load failure

Don’t call `(window.AudioContext || window.webkitAudioContext)()` if platform is IE

Catch any other errors, and display Browser unsupported in error-boundary.

If for some reason there are no other errors (unlikely), preview-modal will still check for IE and show the unsupported modal.

Polyfilling Object.assign is enough to get through load and show the modal for IE. We can always switch to `babel-polyfill` if there are others needed later, but for now this is smaller.

Temporary message when the GUI has an unhandled error

Fix firefox display and functionality issues with sound edit

Reorder motion category

temporary patch for #1205.

Add Error Boundary (has componentDidCatch method) to handle WebGL errors and display an informative message. 

Update scratch-l10n to the latest version 

* Update libraries re: feedback. Resolves GH-1182 GH-1187 GH-1188 GH-1189 GH-1184

* Rename astronaut in space theme

center/size stage-header controls in the same way as stage in fullscreen

Fix duplicate birthday sound clips