Write() doesn't work properly for non-newline terminated strings.

[GoogleCodeExporter]

For a trivial program using Write() without a trailing newline:

            auto pdf = boost::shared_ptr<FPDF>(new FPDF());
            pdf->AddPage();
            pdf->SetFont("Arial","B",16);
            //pdf->Cell(40,10,"Hello World!");
            pdf->Write(5,"Hello World!");

The output file is blank instead of the appropriate 'Hello World' text.

I believe there's a typo in fpdf.zz, line 1581.  The line currently says:

            stmp = s.substr(j, j);

But this results in an incorrect length for the substring.  I think the call 
should be:

            stmp = s.substr(j, i-j);

Original issue reported on code.google.com by aoren...@gmail.com on 23 May 2013 at 8:36