Fix #58: Fix xref formatting in pdf
The html version had keywords, macros, and special vars printed in a fixed-width font as expected. However the pdf manual did not. Fix up the macros so the pdf manual also uses a fixed-width font.
The html version had keywords, macros, and special vars printed in a fixed-width font as expected. However the pdf manual did not. Fix up the macros so the pdf manual also uses a fixed-width font.