set pageIndex of bookmark to NSNotFound when it's not in the dictionary
set pageIndex of bookmark to NSNotFound when it's not in the dictionary
ycaihua/skim-app,WoLpH/skim,ycaihua/skim-app,ycaihua/skim-app,WoLpH/skim,ycaihua/skim-app,ycaihua/skim-app,WoLpH/skim,WoLpH/skim,WoLpH/skim