New Feature: Wispering

Hello!

I would like to be able to communicate with friends in other servers that I have not been invited to, but without taking them out of the server voice group.

I'm suggesting a whispering feature (I'm taking this from TeamSpeak) in which I will be able to send voice to friends that allow me to do it (whitelist) independently where they are.

Configurations for this feature could be:
 - whitelist friends that will be able to talk to me anywhere.
 - Turn down the volume of the actual voice group while I listen to the whispers.
 - Turn down the volume of the whispers instead of the voice groups I'm talking to.
 - shortcut to whisper specific friends.
 - Push to answer last whisper (only him/her can listen).

I know this can be a little hard but this together with Voice messages and Poke are the only features I can see discord is missing to become the ONE application to solve it all!

Thank you for all your hard work. Some of us really appreciate all your efforts.