This patch will return any data get-bytevector-n received and throw error
when get <eof>.
Actually, it's not the same feature in the old version thread
http://lists.gnu.org/archive/html/guile-devel/2012-03/msg00116.html
The old version is complicated because it catches *any* exception and
return the received data within exception.
But this new version is an easy one.
My point is, read-response-body is a low level procedure, so we shouldn't
make it complex. But our current doesn't return received data when the
received data is less than the content-length. I think it should return it,
and let the user determine whether it's an error or continue reading.
And if any one need a more complicated handler, it's better to write
his/her own body reader. My vote is to write a high level HTTP library to
deal with the complex situation.
