[Libdlo] Synchronous vs. asynchronous USB

[Bernie Thompson]

Hi Phil,

Separating encoding from transport to the extent that makes sense,
making the code thread safe, and eventually moving to libusb 1.0 --
are all very good directions to head in.  We're running a little slow
on getting patches in -- but any new patches anyone develops for their
own needs, and which improve the code in these areas, are definitely
welcome.

Does anyone have datapoints on how universally libusb 1.0 is getting
distributed now? In particular, in terms of older Linux distros and
non-Linux OSes -- it'd be great to know where support stops.  My
suspicion, given what I see in the docs right now, is we would limit
the portability of libdlo a little too much to take that dependency
right now.  But would be great to hear other thoughts.

Thanks,
Bernie