* Implement new system calls in the kernel: statvfs(), fstatvfs(),

* Implement new system calls in the kernel:  statvfs(), fstatvfs(),
  fhstatvfs().

* Implement a new VFS op, VFS_STATVFS().  Implement a default for this new
  op for VFSs which do not implement VFS_STATVFS(), which calls VFS_STATFS()
  and converts the structure (using Joerg's conversion procedure from libc).

* Remove statvfs(), fstatvfs(), and fhstatvfs() from libc.  These functions
  are now system calls.