Refresh master with initial release/0.24 snapshot (#332)

* Initial port of release/0.24 source code

* Fix additional headers

* Fix a typo in launch.json

test/smoke/src/areas/workbench/viewlet.ts

@@ -0,0 +1,18 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { SpectronApplication } from '../../spectron/application';
+
+export abstract class Viewlet {
+
+	constructor(protected spectron: SpectronApplication) {
+		// noop
+	}
+
+	public async getTitle(): Promise<string> {
+		return this.spectron.client.waitForText('.monaco-workbench-container .part.sidebar > .title > .title-label > span');
+	}
+
+}