uchcom update

Yesterday I committed some changes to uchcom (so far, only in CURRENT).
Commits are r333997 - r334002.

If you have a CH340/341 based USB<->RS232 adapter and it works for you, could
you please test that it still does?
If you tried your adapter in the past and it did not work, there is a chance it
might start working now.  Could you please test that as well?

Thanks!
-- 
Andriy Gapon