[NFC] Add display name for custom React components

This improves readability of "Components" tab from React Development Tools extension for Chrome

shared/naturalcrit/splitPane/splitPane.jsx

@@ -5,6 +5,7 @@ const _ = require('lodash');
 const cx = require('classnames');
 
 const SplitPane = createClass({
+	displayName : 'SplitPane',
 	getDefaultProps : function() {
 		return {
 			storageKey   : 'naturalcrit-pane-split',
@@ -77,6 +78,7 @@ const SplitPane = createClass({
 });
 
 const Pane = createClass({
+	displayName : 'Pane',
 	getDefaultProps : function() {
 		return {
 			width : null