v0.7.0: Add a bunch of convenience features

Microsoft Windows only:
    - Only allow a single instance
    - Always on top option
    - Touch/click doesn’t steal focus
    - Events triggered without having to activate the window fist

- Automatically try to reconnect with exponential backoff
- Implemented command timeouts per spec
- Fixed volume calculations and display at extremes
- Disable shortcuts for disabled buttons
- Disable volume buttons at extremes
- Improved debugging system
- Update readme and screenshots