Helpers parse response bug

Hi all,

I think I found a bug in the current helpers response parsing code: One
byte remains in helpers io buffer after parsing the response. This is
will cause problems when the next response from helper will enter squid.

The bug exist in helperHandleRead and helperReturnBuffer functions exist
in src/helper.cc file.
After the srv->rbuf parsed, the srv->rbuf still contains on byte (a
'\0' char) and the srv->roffset is 1.

I am posting a patch which fixes the problem.
Also a second patch (helpers-fix-alternate.patch) to help you understand
the problem.

Regards,
   Christos