[2.0] Splash screen

A question was raised on IRC by tinman if the splash screen plays a role. Its purpose is to tell the user is software is loading. But

* On Mac OS X, most software don't use splash screens, instead the dock icon is bouncing up and down to indicate that the software is being started
* On Windows for traditional desktop software a splash screen is a common standard among software that take time to load
* In apps for the Windows Store, a splash screen is required.
* Gnome shell has an app menu that also shows a loading indicator, so no splash needed
* Ubuntu shows an animation on the icon, so no splash needed either

So only Windows kind of requires the splash screen. We can fix this in the build script.