Use PureComponent for performance boost on libraries

src/containers/costume-library.jsx

@@ -7,7 +7,7 @@ const costumeLibraryContent = require('../lib/libraries/costumes.json');
 const LibraryComponent = require('../components/library/library.jsx');
 
 
-class CostumeLibrary extends React.Component {
+class CostumeLibrary extends React.PureComponent {
     constructor (props) {
         super(props);
         bindAll(this, [

src/containers/sound-library.jsx

@@ -9,7 +9,7 @@ const soundIcon = require('../components/asset-panel/icon--sound.svg');
 
 const soundLibraryContent = require('../lib/libraries/sounds.json');
 
-class SoundLibrary extends React.Component {
+class SoundLibrary extends React.PureComponent {
     constructor (props) {
         super(props);
         bindAll(this, [

src/containers/sprite-library.jsx

@@ -7,7 +7,7 @@ const spriteLibraryContent = require('../lib/libraries/sprites.json');
 
 const LibraryComponent = require('../components/library/library.jsx');
 
-class SpriteLibrary extends React.Component {
+class SpriteLibrary extends React.PureComponent {
     constructor (props) {
         super(props);
         bindAll(this, [