Uses the old 4-clause BSD license, GPL-incompatible

[joshtriplett]

Airplayer uses the old 4-clause BSD license, with the attribution clause. This makes it incompatible with GPLed software, making it impossible to write GPLed backends for Airplayer. Please consider switching to either the newer 3-clause BSD license or the MIT license.

[pascalw]

Hi Josh,

thanks for the suggestion, I will consider it.

[joshtriplett]

Much appreciated, thanks.