Fix for serif font not being applied correctly to PDF

Replacing the variable with the equivalent string literal worked, so
I’m not sure quite what’s going on here. However, stripping the
double-quotes out of the string fixes the problem.
Merge branch 'uoldmp-export/format-settings'

Some presentational issues to be addressed, but functionality is there. Need to think about how we present the options to users, what range of sizes/margins are appropriate and how best to describe the font face options.
Merge remote-tracking branch 'upstream/master' into export/space-used