Merge branch 'develop' into sprite-save-load

package.json

src/components/action-menu/icon--search.svg

src/components/menu-bar/menu-bar.jsx

src/components/monitor-list/monitor-list.css

src/components/sprite-selector/sprite-list.jsx

src/components/sprite-selector/sprite-selector.css

src/components/sprite-selector/sprite-selector.jsx

src/components/stage-selector/stage-selector.jsx

src/components/stage/stage.css

src/containers/blocks.jsx

src/containers/costume-tab.jsx

src/containers/language-selector.jsx

src/containers/menu.jsx

src/containers/sound-tab.jsx

src/index.js

src/lib/app-state-hoc.jsx

src/lib/connected-intl-provider.jsx

src/lib/hash-parser-hoc.jsx

src/lib/libraries/backdrops.json

src/lib/libraries/costumes.json