Think about when to replay file operations and when not to

[pkmoore]

For example:

We don't want to replay "open" calls that result in file descriptors that are eventually mmap()'d
We don't want to replay write calls that are output that tell us how the program is responding to our injections
We might want to replay write calls to file descriptors that update program state that we are replaying later (or maybe this doesn't matter)