Blacklist, custom command fixes, and server administration role

• A list of users can be specified in config to be permanently ignored
  by CadenceBot. If desired, this can include CadenceBot itself, to
  prevent the bot from replying to itself (This is now done in
  production).
• Randomized custom commands are now properly overrided (if both are
  arrays, the arrays are merged)
• Custom commands and long-reply commands now pass output via the
  sendLong mechanism, which allows the sending of messages past
  Discord's character limit (With italicized spaces!)
• A single user can be specified as the Administrator for a particular
  CadenceBot instance. Certain commands (currently maillog and config -
  see below) are only runnable by the Administrator
• A new command allows the bot to echo the pretty printed JSON of the
  current configuration to the channel. This is admin-only.
  Additionally, the same pretty-print is logged (debug) on bot start.