Allow CoreCycler to increase negative CO offset automatically

[fscottcopeland]

Hey,

Current CoreCycler implementation is to only ever reduce the negative CO offset, never to increase it.

However, it would be really really useful if this sort of feature was available. It would be great to be able to start an automatic test, and let CoreCycler run while I'm out at work, gradually adding a bigger and bigger negative CO offset until it is unstable. That way, far less intervention would be required.

Currently, only option is to overdo the negative CO offset and hope that it isn't unstable enough to fully crash the PC, only unstable enough to fail the test.