When document.attributes['header'] == 'no', do not insert preamble or any other bolier plate.  NEED TO CHECK: whether the output when embedded? is true is still correct.
When document.attributes['header'] == 'no', do not insert
preamble or any other bolier plate.  NEED TO CHECK: whether
the output when embedded? is true is still correct.

jxxcarlson/asciidoctor-latex,PissedCapslock/asciidoctor-latex,jxxcarlson/asciidoctor-latex,asciidoctor/asciidoctor-latex,PissedCapslock/asciidoctor-latex,asciidoctor/asciidoctor-latex,jxxcarlson/asciidoctor-latex,asciidoctor/asciidoctor-latex,PissedCapslock/asciidoctor-latex