a) readdir cookies and eofflag
b) file handle routines.
File handle routines are REALLY ugly and are not stable, i.e.
the file handle will be lost if the file server goes byebye.
They probably should be redone to not use getfh(), but for nullfs
I wanted to make them the same as when the file system is accessed
without the null layer. Well, turns out it doesn't pass anyway
since the kernel adds the fsid tags for fhandle_t. Anyway, it's
useful for some limited hacking purposes, so I'll commit this
since it works .. kinda.
a947a86fee