Enable selection of sprite visibility by keyboard.

Show focus on language selector.

Hide icons from screenreader

Update all react 16.1.0 related dependencies together

Add alternate text for Scratch logo.

Wire up ask/answer components to the stage

Prevent switching tabs while one of these blocks is glowing from
crashing because it is given a new ID.

Use scratch-ll10n for extracting strings

Add music extension

Update enzyme-adapter-react-16 to the latest version 

Add aria label to language selector.

Add ask and answer blocks

Update react-style-proptype to the latest version 

Add Lego WeDo 2.0 extension to library

Add compatibility testing example page

Scroll to extension category only when loading from library

Load extension library data from a js file