status = doc:UseJPFonts()
doc:UseJPFonts() enables Japanese fonts. After doc:UseJPFonts() has been called, an application can use
the following Japanese fonts:
When doc:UseJPFonts() succeeds, it returns #HPDF_OK. Otherwise, it returns an error code and the error handler is invoked.
#HPDF_INVALID_DOCUMENT - An invalid document handle was set.
#HPDF_FAILED_TO_ALLOC_MEM - Memory allocation failed.
#HPDF_DUPLICATE_REGISTRATION - The font of the same name has already been registered.