Mark warnings as "not to be silenced"
Mark warnings as "not to be silenced"

We want the tavl code to stay as close to Ben Pfaff's original as
possible, so we do not silence its few warning messages.

jeffreykegler/libmarpa,jeffreykegler/libmarpa,jeffreykegler/libmarpa,jeffreykegler/libmarpa,jeffreykegler/libmarpa