related to #17108 #26484

* Replace focussed with focused

* Replace Focussed with Focused

* Update definition of Promise in winjs.base.d.ts.

* Update to new Promise declaration

* Fix remaining errors.

* wip

* fix for windows

* add some tests

* only run multi root test on windows

* fix bug with opening files into a workspace that opens (enables smoke test)

* document how to run against out of source

* enable test for all OS

fixes #30698