Possibility to append '--debug' to the command line
Update documentation about the '--debug' argument
MSSLinux: refactor enum_display_monitors(), add XFCE4 support
MSSLnux: fix typo in comment
MSSMac: little refactoring into enum_display_monitors()
MSSWindows: little refactoring into enum_display_monitors()
Update documentation about enum_display_monitors() refactoring