Move all commands to the client

[KKosty4ka]

this should remove redundant code (server side command parsing) and allow scripts to use simple network functions instead of messing with command strings and fishing out responses from chat (like in #46)

also, this will make #111 easier (the server won't have to keep track of lang settings)

[KKosty4ka]

commands roughly in order of complexity:

• /uptime
• /whoami
• /test
• /delete
• /worlds
• /channel
• /mute & /clearmutes
• /tell
• /block(user) & /unblock(user/all)

[KKosty4ka]

other things after that:

• fix bug: using /tell adds extra entry to chatWriteHistory with only the message content
• /passive can just be removed
• completely move /help (it's done on the server, but the client hacks its commands into the message)
• hide some commands (/worlds, /mute, /delete, etc.) from /help if the user can't use them
• hide /uptime from /help if the user isn't an operator (even though they can use it..?)
• really make sure chat ratelimits affect /tell
• catch invalid commands on the client
• add a response to invalid args (e.g. /block dsfds)
• test blocking/unblocking even more thoroughly

[KKosty4ka]

there's probably a better place for stuff i put into chat_mgr.js and utils.js