net-im/abaddon: New port: Alternative Discord client with voice support

Made with C++ and GTK 3.

Current features:

• Not Electron
• Voice support
• Handles most types of chat messages including embeds, images, and replies
• Completely styleable/customizable
• Identifies to Discord as the web client unlike other clients so less likely to be falsely flagged as spam
• Set status
• Unread and mention indicators
• Notifications (non-Windows)
• Start new DMs and group DMs
• View user profiles (notes, mutual servers, mutual friends)
• Kick, ban, and unban members
• Modify roles and modify members' roles
• Manage invites
• Manage emojis
• View audit log
• Emojis
• Thread support
• Animated avatars, server icons, emojis (can be turned off)

PR: 288157