index.html, main.coffee: Convert URLs in messages into links
index.html: Add placeholders for the input fields
main.coffee: Add a number at the end of the nickname if it conflicts
main.coffee: Handle invalid server responses better
main.coffee: Call init() when the connection is closed
main.coffee: Show nickname changes in non-verbose mode
main.coffee: Add a command to reload the page
main.coffee: Auto scroll only if the user has scrolled to the bottom