Configure for new Sentry account

Add 100 new sounds to library

Add Google Analytics

Remove some blocks’ menu shadows to make them non-droppable

Merge pull request #1240 from LLK/greenkeeper/scratch-vm-0.1.0-prerelease.1515771598-prerelease.1515771612

Update scratch-vm to the latest version 

Fix Firefox sound recording

Use style sizing to fix issues with Edge + flex + canvas.

Use new renderer methods to check for WebGL.

Update scratch-audio to the latest version 

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 

Additionally render the canvas at a multiplier of the device pixel
ratio, so we get hidpi images for supported screens. The fixed CSS
sizing allows us to do that.

The problem was that on Edge, flexbox apparently can grow canvas
elements, whereas on Chrome/FF the canvas width/height is respected. No
problem, we can set the width/height in CSS to fix it, which
conveniently allows us to also fix the low-res-on-retina-screens problem
at the same time.

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.