MAI Unit test of simple send/recv between two processes

To test that the MAI stack is active start ar reader in one window
 ./htest -d 0 -p 6   -l 100 -r 1  -m 4
then in window B start the writer
 ./htest -d 0 -p 6  -l 100   -w 1 -m 4

The writer will send INTERNAL mads and the reader should pick them up.
This validates the MAI stack to be operational

