[ft] How do I iterate over each kerning pair?

[Vinnie]

I know that you can use FT_Get_Kerning() if you want to retrieve the kerning 
for a specific pair of glyphs but what if I just want to loop over all of the 
available kerning pairs and get the information? I'm trying to transfer all the 
data in a FreeType FT_Face into another object in a 3rd party drawing framework.