[avr-chat] FatFS LFN Support

[Jim Brain]

While I was lurking and piddling around implementing FAT16/FAT32 LFN 
code as a hobby in the last 2 years, FatFS showed up.  Now that I am 
getting back into things, I spent last week working through all the 
details of adding LFNs on file creates in my codebase, only to find 
FatFS.  As such, instead of creating yet another FAT16/FAT32 codebase, I 
am modifying FatFS to include LFN support.

file reads, dir reads, and file open/writes seem to work, though I just 
got the code working tonight.  I am looking for folks who have used the 
library, as there are things I don't understand about the FatFS logic, 
and I need some additional testing (eyeballs) to look at the code.

To make testing easier, I imaged an actual CF card here and wrote a 
simple stub diskio.c that simply reads and writes the image.

Jim