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

#6919

fixes #6781

Exposes the workbench.files.action.openRecentlyClosedFile command that opens
the file or files most recently removed from the working files list.

Part of #3989

This reverts commit 9a15f9e3.

The unsaved file marker (the dot thing) should appear when content in buffer != content on disk (fixes #2357)

# Conflicts:
#	src/vs/languages/html/common/htmlTags.ts