Never launch in fullscreen mode

[mirka]

Closes #739

Continuation of @rakhi2104's work from #904

This ensures that the app always launches with Fullscreen Mode disabled.

Due to a strange difference in behavior, a single approach was insufficient. After some experimentation, it turns out that we need to take a different approach depending on platform:

• Mac → Disable fullscreen mode on window close
• Win & Linux → Disable fullscreen mode on launch

To test

It would be better to test with the actual builds:

• Mac & Linux: https://circleci.com/gh/Automattic/simplenote-electron/1579#artifacts/containers/0
• Windows: https://ci.appveyor.com/project/Automattic/simplenote-electron/builds/20198046/artifacts

Steps

1. Launch Electron app and set to Full Screen mode (View menu ▸ Toggle Full Screen)
2. Quit app
3. Relaunch app, and make sure that it is not in Full Screen mode

[roundhill]

I've tested:

• Linux
• Mac
• Windows (will get to it tomorrow!)

[roundhill]

All 3 platforms now tested