Added !server, !join and some general improvements

Audio's task now properly checks if the audio module is still loaded
Added !server to cogs.general for server info
Added !join <invite> (owner only) to make Red join other servers
settings.json now gets deleted if login fails

cogs/mod.py

@@ -2,7 +2,6 @@ import discord
 from discord.ext import commands
 from .utils import checks
 from .utils.dataIO import fileIO
-import __main__
 import os
 
 class Mod: