[IDEA] AirPlay 2 support (including multiroom)

[mtavares]

Based on the statement below from the Shairport-sync maintainer ut does not appear to be ready for production use. 

Code:

"This code is experimental and much of the normal functionality of Shairport Sync is broken. Please do not use it in situations where reliable service is expected."

@Tim Curtis
Thanks by your information. I saw at the Github that the persons that are experimenting this new Airplay 2 version is having good results, particularly related to the YouTube integration.  Let's keep track of the progress of this Airplay 2 development in order to allow the  MoOde integration  when the reliability level has been achieved.

Thanks. QJA