Relax rules on valid guild name characters, and update guild key generation function to reflect this. Enforce automatic namespacing of guild name keys with key generation function, and remove manual namespacing everywhere else. Change various 'key' variable names to 'guild_key' to better portray their purpose. Add a 'temporary' registration option, which forgets a guild after 24 hours. Tidy up some CSS and hide 'Register' link when logged in.