- OSX readlink doesn't have the -f or -m options, require correct PAPARAZZI_SRC to be set already for now
- using xauth with docker on OSX doesn't work, so we use socat to forward the socket via TCP
- see https://github.com/docker/docker/issues/8710
- no (pulse)audio on OSX...
- find on OSX doesn't have the -printf option... so use exec echo instead
this will hopefully fix#1421