Achieve feature parity

[tec27]

• Keep a finite number of messages
• Pause/resume videos as they go out of/come into view
• Add mute functionality
• Add timestamps to messages
• Add gif saving
• Add camera switching
• Add an error display when webrtc/videos fail to initialize
• Use https
• Support linkification (meatspace's and otherwise)
• Add a progress bar for recording
• Handle aspect ratio preservation properly
• Working character counter
• Unread count in favicon
• Disable input/submit while submitting
• Don't add duplicate videos to the DOM (only request newer ones?)
• Limit message sending on both client and server
• Deal with mobile zoom and look decent there
• Have a README
• Built in time-delay messaging
• Prevent self-muting