void set_auto_include_string(s)
string s

If called, the string s is prepended to every file compiled after that. If
If there are errors within it, line numbers will range from -n to 0. Updating
the master will clear the string. Thus it was to be called from reset()/
create() in the master and reactivate_master. Maximum length for s is 25k.
Calling it from outside the master will cause a privilege violation.
