inventing and providing our own. Hopefully this solves a HP-UX 11.00 problem.

added TFTP to the list of supported protocols

glibc versions, and with this patch applied it no longer shows up to me. The
problem was indeed a flaw that made curl use a file handle already closed.

of the end of a chunked-encoded POST request.

Should we do this for all targets?

have this check done on far too many places by now...

added. TODO: add them to docs. add TFTP server to test suite. add TFTP to
list of protocols whereever those are mentioned.