Tightens SRCF shutdown

BaronOhShi reported on the IRC that the SCRF terminal let you seal it repeatedly, allowing an unlimited amount of explosions for all the pyros in the playerbase.

This adds a clear-options and shutdown, along with printing a few messages to the screen where the explosions promptly overwrite 'em.

Thanks for reporting.
Merge pull request #10510 from KA101/sarc

Tightens SRCF shutdown