JitsiMeetJS#init accepts an options object in which the property
disableAudioLevels may optionally be defined and is meant to disable RTC
statistics related to audio levels. Unfortunately, the option was used
in a boolean expression which ignored the value of the option and thus
effectively rendered it unused.

While we have JitsiMeetJS defined as a global variable in Jitsi Meet, it
doesn't sound like an absolutely necessary and beautiful requirement
inside the library itself.

es6-promise.polyfill() is broken for Chrome atm and replaces the native Promise and swallows unhandled errors.
https://github.com/jakearchibald/es6-promise/issues/70