Logging of MSG_COUNT

[hullas1502]

format: PERF.SG.SEND_MSG_COUNT : sgid, superstep_num, sg_msg_count,broadcast_msg_count,total : messages sent per superstep

*sendToAll increases broadcast_msg_count by 1. So use: total msg count = sg_msg_count + total_sg * broadcast_msg_count

Issue: Sum of all sent messages in ith superstep is not equal to sum of all received messages in (i+1)th superstep.
Typically, send_msg_count << recv_msg_count