stat (AGAIN!)

[COLLOT Jean-Yves]

Using your method instead of opendir() readdir() seems very interesting, and
will certainly give better performances. When your version of VMS_OPENDIR
works, I'll be happy to put it in the distribution.

Please check that it works too with ODS-5 file system, with the extended
file names !

For information, I checked the efficiency of the directory/stat memory
caching. It's about the same for both caches. Even when doing numerous
changes (file creations/deletions) the number of disk I/Os is divided by
about 4. 
When only browsing, it's obviously far more ( > 10) .