Adds a note at the specified point.
pdf_document
The document handle, returned by cpdf_open().
llx
Lower left X
lly
Lower left Y
urx
Upper right X
ury
Upper right Y
title
The title of the annotation
text
The contents of the annotation
mode
The optional parameter mode
determines the unit length. If it is 0 or omitted the default unit as specified
for the page is used. Otherwise the coordinates are measured in postscript
points disregarding the current unit.