Lower the large-file threshold to 64K
Lower the large-file threshold to 64K

Yes, I'm quite miserly when it comes to memory usage.  Since the
file is already on disk, just read it incrementally and stream
it out to avoid having to deal with potential memory exhaustion
issues on busy systems.  There's also no benefit to slurping
256MB and anything above 64K leads to diminishing returns on
most systems I've seen.

songkick/mogilefs-client,drasch/mogilefs-client,godfat/not-used-mogilefs-client