A global shortcut/hotkey for Desktop Qt-Applications.

The QHotkey is a class that can be used to create hotkeys/global
shortcuts, aka shortcuts that work everywhere, independent of the
application state. This means your application can be active,
inactive, minimized or not visible at all and still receive the
shortcuts.

Features
- Works on Windows, Mac and X11
- Easy to use, can use QKeySequence for easy shortcut input
- Supports almost all common keys (Depends on OS & Keyboard-Layout)
- Allows direct input of Key/Modifier-Combinations
- Supports multiple QHotkey-instances for the same shortcut (with
  optimisations)
- Thread-Safe - Can be used on all threads (See section Thread safety)
- Allows usage of native keycodes and modifiers, if needed

Note: For now Wayland is not supported, as it is simply not possible
      to register a global shortcut with wayland.