Fork Chatty

This is fork of Chatty with some improvements and without any breaking changes of original version.

List of added features.

Load recent messages of channel.
Mention user by middle click.
Shortcut to Livestreamer window through context menu.
Title of youtube video in url dialog.
See images in Chatty.
- Left click — close window.
- Middle click — copy image in clipboard.
- Right click — save image on hard disk.