Cleanup non-ascii characters and cleanup patch FAT on non standard sector size devices

This patch series contains a cleanup of the use of non-ascii characters in FAT-fs files, and also a cleanup of a patch originally posted by Igor Luri. However, the patch posted by Igor on the mailinglist was still not readable (base64 inlined patch) and thus not mergable or testable.

So, I merged the whole patch by hand and here is a repost...

Igor, can you please check if I did this cleanup properly.

Notice that the code that the original fat-code here does not match _any_ coding rule standard and is actually a big mess. So, I did not focus on the Coding Rules too much for this patch.
I will post a seperate patch to fix this for these files also.

Kind Regards,

Remy