[syslinux] COMBOOT API: Add calls for directory functions; Implement for FAT

[H. Peter Anvin]

Gene Cumm wrote:
> 
> Aside from the obvious fact that SYSLINUX needs to be compiled for the
> local codepage (in order to properly use the long name), that should
> make a complete solution.
> 

I've been meaning to make it possible to load a codepage dynamically. 
It's actually pretty trivial, just haven't gotten a tuit of the 
appropriate shape yet.

	-hpa