Merge pull request #227 from paulkaplan/sprite-delete-button

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

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

src/components/close-button/icon--close.svg

src/components/modal/modal.css

src/components/modal/modal.jsx

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

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

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

src/components/target-pane/target-pane.jsx

src/containers/sprite-selector-item.jsx

src/containers/target-pane.jsx