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

This reverts commit bf5774af.

Clicking on the dock when no window is open should open a new window, not reopen the last one

related to #5658

* electron bump

* oss bump

* adopt missing will-quit call when using process.exit()

* more bgcolor fixes

* add comment

fixes #4400