new logFile management: logFlag removed, activation from cmd line, a bit of refactoring.
new prompt to avoid confusion with the program output received by the serial link.
new default values: 9600 8N1 no control flow nor mapping carriage return to new line on output.
a few traces added.
new program's traces management.
a bit of code reformatting and cleanup.
Merge https://github.com/Oliviers-OSS/microcom