uio parameter; if it's not null, the data are copied directly
into/from the user buffer via uiomove()
new macro NTFS_U28() and function ntfs_u28() to convert between Unicode
and 8bit encoding; all it does currently is getting lower 8bit
of the Unicode char and subtituting '_' for it if the result would be 0;
use the macro within NTFS_TOUPPER() macro and in ntfs_uastrcmp()
g/c the (ntfsmount *) parametr to ntfs_u*astr[i]cmp() functions, it's no
longer needed
avoid excessive intendation
2f7c750c12