Actors benchmark

Compare different languages/framework on actors model implementation.

The algortihtm is described here: https://www.sics.se/~joe/ericsson/du98024.html

Feel free to PR your preferred framework/language implementation.

Usage

Each dir should contain a Makefile with default rule:

compiling the code
run the benchmark handling the following env var:
- ZOG_THREADS = number of threads in the ring (default to 1000)
- ZOG_MSGS = number of exchanged messages (default to 1000)