Parrot v0.6-alpha

Another major update! Woohoo!

• Migrated to final Swift 3.
• Authentication flow is fixed and works again.
• Cleaner animations here and there.
• Restore open conversations when reopened.
• Added some URL scheme + AppleScript support in places.
• Conversations can be muted now!
• Notifications work for real!
• Settings drawer for conversation control.
• AND LOTS MORE!