- added the original source/idea as a comment to the code.
- Added what is basically one of the corner-stones of my DOS environment.
  I have the start_dos.bat executed first, every time a cmd window is opened. It loads up the doskey variables (via `alias.bat --load`).
  The exit_dos.bat file is used to close the window. It saves the current doskey variables to the settings file (`~/.doskey_macros`).