Vscode merge (#4582)

* Merge from vscode 37cb23d3dd4f9433d56d4ba5ea3203580719a0bd

* fix issues with merges

* bump node version in azpipe

* replace license headers

* remove duplicate launch task

* fix build errors

* fix build errors

* fix tslint issues

* working through package and linux build issues

* more work

* wip

* fix packaged builds

* working through linux build errors

* wip

* wip

* wip

* fix mac and linux file limits

* iterate linux pipeline

* disable editor typing

* revert series to parallel

* remove optimize vscode from linux

* fix linting issues

* revert testing change

* add work round for new node

* readd packaging for extensions

* fix issue with angular not resolving decorator dependencies

src/vs/platform/theme/test/common/testThemeService.ts

@@ -12,12 +12,12 @@ export class TestTheme implements ITheme {
 	constructor(private colors: { [id: string]: string; } = {}, public type = DARK) {
 	}
 
-	getColor(color: string, useDefault?: boolean): Color | null {
+	getColor(color: string, useDefault?: boolean): Color | undefined {
 		let value = this.colors[color];
 		if (value) {
 			return Color.fromHex(value);
 		}
-		return null;
+		return undefined;
 	}
 
 	defines(color: string): boolean {