Right now code like this does not work:

conf := &model.Configuration{} // assuming sane defaults for zero object here
// do any kind of writing with this configuration

It turns out that at least Eol should be set for any PDF generation, else empty string is used (is it ever useful to have empty string there?).

Also there are several places related to PDF optimization:

• conf.cmd == model.OPTIMIZE
• conf.Optimize = true
• conf.WriteObjectStream
• conf.WriteXRefStream

Is there any reason to have optimization configuration split like this?