LaTeX export: More tuning for the options import

LaTeX export: More tuning for the options import

Russel Adams writes:

>  That worked, the only point I may make would be to exclude
>  LATEX_HEADER and TEXT from that list.
>
>  I'm also trying to resolve an ordering issue. I want to have a
>  header/footer line declared in the header, but I want to use these
>  orgTITLE macros in that. Currently LATEX_HEADER and the class go first
>  before the definitions, and TEXT occurs inside the document. If the
>  macro isn't defined before the header/footer, you get an error.
>
>  I may have to manually code those, which defeats the purpose of using
>  the org options.

OK, I removed those two fields, and I switched things around so that
the new macros are defined earlier.