Return the HTTP protocol version, and close the connection if we're 1.0.

At least one HTTP/1.0 server doesn't support keepalive but also doesn't
close the connection.  This forces the us to close the socket if the
server has reported it's only 1.0.
Add documentation and a comment for the HTTP/1.0 connection closing
Fix up this bizarro fetch initialization

Nothing in the rest of this function does any sanity checks so let's
just assume we have the $fd like everything else, and also split up
variable declaration from variable assignment.
Consistency in how we pass errors around

The other passing around of Hijk::Error::*TIMEOUT* is returning the
constant and not the hash we should return, do the same here for
consistency.