[ft] lsb/rsb_delta and vertical layout

[Brady Duga]

I was interested in implementing the lsb/rsb_delta code to account  
for rounding in autohinted text, but I am curious how this would work  
for vertical text. My application supports both horizontal and  
vertical text rendering. I think I understand what to do for  
horizontal text, but how do I handle vertical? It seems like I would  
need tsb/bsb_delta values. Is this just not supported in the current  
FreeType, or am I missing something?

--Brady Duga