[Fix] Serialization / deserialization of enter factor...

[kiplingw]

Serialize and deserialize the user's enter factor parameter.

[yurymalkov]

That would break the compatibility between saves done with different versions.

[kiplingw]

True. One way to fix that, albeit not retroactively, is to write out a binary version and check it when reading back. Thoughts?

[yurymalkov]

I think if the change is made it needs to be backwards compatible (e.g. an old checkpoint without version would still be loaded).

[kiplingw]

It's difficult to reliably determine older data since the first data written out is a size_t which could have a value of anything.