- Improved the command line generation, by removing the additional thread which was checking for the possible existence of the 'sigwrite' file. The new check for the existence of this file is done in the already existing generation thread (idea and code suggested by Michael Chourdakis). - Minor improvement: the History states will now be stored in four std::deque-s instead of four std::list-s (but the improvement is not noticeable in practice). - Minor improvements.