This will see the maximum allowed of modes that are allowed at once as sent in RPL_ISUPPORT
and will send multiple batches while using /op, /voice, etc.
This also fixes a minor issue where it would try sending an empty voice if it had an extra space on arguments
(such as using '/voice ')
Several ES6 additions are only available in strict mode. Example:
> SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode
Strict mode was also enabled in a few of our files already, and it is a good thing to have anyway.