eliminate warnings
those are done
update more docs
actually, OPTIONS won't have response body...

so let's simply return the headers
make hijack easier to use by returning the socket if we're hijacking
future socket so that we could obtain the socket synchronously

e.g.

    sock = RC::Universal.new.get('path', {}, RC::HIJACK => true)
    sock.gets
    sock.gets
bump docs...