Fix multiple instances

• Add a fix to keep a single instance of the app only
• Fix download progress in updater

Keep it opened!

• Add system tray to keep the app opened and notifications works on close
• Add notification badges for Windows (on the taskbar)
• Dynamic title based on the active conversation
• and other minor fixes

Enjoy!

Bug fixes & auto-updater

• Fix updater window
• Add Menu with about window
• Add auto-updater

First release

Enjoy!

MacOS and Linux cannot be available except you'll build for me :)