Merge branch 'develop' into immutableMonitors

package.json

src/components/close-button/close-button.css

src/components/close-button/close-button.jsx

src/components/filter/filter.css

src/components/filter/filter.jsx

src/components/filter/icon--filter.svg

src/components/filter/icon--x.svg

src/components/library-item/library-item.css

src/components/library-item/library-item.jsx

src/components/library/library.css

src/components/library/library.jsx

src/components/modal/modal.css

src/components/modal/modal.jsx

src/components/monitor/monitor.jsx

src/containers/backdrop-library.jsx

src/containers/blocks.jsx

src/containers/costume-library.jsx

src/containers/sound-library.jsx

src/containers/sprite-library.jsx

src/css/units.css