A max external which uses zmq to connect to a separate python process

The objective is to replicate what the py external does but using zmq.

brew install zmq

• proof-of-concept

• how to launch python server automatically and close it with the patch

• run as subprocess and read and write from stdin and stdout via a pipe

• https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/CreatingLaunchdJobs.html

• https://github.com/sheredom/subprocess.h