Remove write permission from generated files

[agazso]

Sometimes it happens that you accidentally edit the generated files. It would help if the generated files doesn't have write permissions, because most editors warn you when trying to edit a read-only file.

[lptr]

While this would fix the problem in a way, I've never heard of a code generator that did this. IMO the best would be to keep Spaghetti as much like other tools as possible.