Hide all floating windows with hotkey +3 features

[Hasami]

Some features that I really miss:

1. A hotkey to hide/show all floating windows (it’s very time consuming to press H X I E)
2. Change image rating using mouse inside the xmp window
3. Show only images with stated rating
4. Manual image rotation

And thank you again for the fastest image viewer!

[Axel]

An F10 hotkey has been added to hide/show all auxiliary windows at once. Now F10, F11 and F12 can be used to quickly "manage" the screen real estate by hiding floating popups, switching to full-screen mode and hiding the taskbar, respectively.