Formatting handling bugs in generators using files as source

[Arthoni]

• In source files, lines with ; as column separator are silently ignored
  the convention is that the space character is used in source files, but if a line is not understood, the system should issue a warning
• Header is not accepted
  if a line starts with a #, the generator may issue a formatting error or ignore the line
• if a filesource is a directory, this will silently block the simulation engine
  If the filesource refers to a directory (which is a user error), the program will run until the "initialize" step and nothing happens anymore, it can only be stopped by a ctrl-c