Filesystem modifications

[jennifer averett]

I have added the patch submitted Till Straumann
with minor modifications.  It will be available in
the next snapshot.

I have a general question for users of the file system
infrastructure code.  If an a fatal error occurs in this
code is it resonable to call rtems_fatal_error_occured.
A location  where this could occur is if a filesystems
unmount fails after the filesystem has been unmounted
from the directory node.  I belive the correct behavior
would be for the filesystem to be reattached to the
directory node.  I am looking for input from what users
would expect to occur if this reattachment fails.

Thanks
Jennifer