BUG/MEDIUM: http: do not restrict parsing of transfer-encoding to HTTP/1.1

BUG/MEDIUM: http: do not restrict parsing of transfer-encoding to HTTP/1.1

While Transfer-Encoding is HTTP/1.1, we must still parse it in HTTP/1.0
in case an agent sends it, because it's likely that the other side might
use it as well, causing confusion. This will also result in getting rid
of the Content-Length header in such abnormal situations and in having
a clean connection.

This must be backported to 1.5 and 1.4.