Adds a note at the specified point.
pdf_documentThe document handle, returned by cpdf_open().
llxLower left X
llyLower left Y
urxUpper right X
uryUpper right Y
titleThe title of the annotation
textThe contents of the annotation
modeThe 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.