Keyboard interrupt during trials should clear mutated cache files

[EvanKepner]

You can end up in a partially mutated cache state (listed in known limitations already), add the catch and controls to clear mutated files in the event of a keyboard interrupt.

Not clear if this is good enhancement, KeyBoard interrupt should remain as a control stopping mechanism, and if you CTRL+C on other commands (like mv or cp) it stops instantly.

[EvanKepner]

Won't do - marked in known limitations documentation.