System customisation: about the "system.se" file.

When starting execution, SmallEiffel first have a look 
in file "system.se" which must be in directory "bin".
This file tell the current system name ("UNIX", "Windows",
"Macintosh", "DOS", "OS2", "Amiga", "VMS", ...).
To have the full list of currently handled system, try to 
put a bad system name in file "system.se" and then, just
run for example command `compile'.

When the system name is correctly set in file "system.se", 
SmallEiffel do some automatic customisations. 
For example, if "system.se" file contains string "DOS",
SmallEiffel uses suffix ".BAT" for script files and suffix
".EXE" for executables files.

