* fakemail.c: Include <ignore-value.h>.

* fakemail.c: Include <ignore-value.h>.

(put_line): Explicitly ignore fwrite return value, for benefit of
recent glibc + gcc.
(close_the_streams): Diagnose output errors instead of merely
exiting with nonzero status.
(my_fclose, main): Diagnose input errors, and exit with nonzero status.
Formerly, input errors were silently ignored.