more restrictions for usernames

[VillainsRule]

latest anti-troll measures.

• rooms are now restricted to a-z characters (as well as - and _).
• rooms are now better filtered for inappropriate words.
• adds a multiplayer name changer to settings.
• checks users for inappropriate names on game join. if a bad username is detected, it is randomized.
• checks users for inappropriate names on change inside of a game. if a bad username is detected, the old username is used.
• adjusted the filters to add a few more words that trolls enjoy using.

i don't think there's ever a way to get rid of trolls entirely, but i'll keep fighting them anyways. nice challenge for myself. :coffee: