examples: update distributed hello to initiate greetings from only one actor

Signed-off-by: George K. Thiruvathukal <gkt@cs.luc.edu>
Merge branch 'master' of github.com:sebhtml/biosal into granularity
hello_acq: Revise code to have clear causality chain (tested on mpirun -np 1..16)

Signed-off-by: George K. Thiruvathukal <gkt@cs.luc.edu>
hello_acq: clean up unneeded debug messages/make output a bit prettier

Signed-off-by: George K. Thiruvathukal <gkt@cs.luc.edu>
Merge remote branch 'gkt/granularity' into energy