Due to issues #14151, #14149 & #14182

Also clean up shutdown logic to fix issue where backup workspaces were not
being evicted from workspaces.json.

jsdoc was only added for the renderer side interface as they will soon
be merged together.

Make content update trigger after dirty status is evaluated

Save file even without file changes - so that Nodemon, Gulp, Chokidar and other file watchers restart (fixes #7470)

see https://basarat.gitbooks.io/typescript/content/docs/tips/nominalTyping.html and https://github.com/Microsoft/TypeScript/blob/7b48a182c05ea4dea81bab73ecbbe9e013a79e99/src/compiler/types.ts#L693-L698