JLdL 21Jan11.

- Prevent fix-quotas and update-quotas from running when a
   cluster-wide text quota file directory is defined (JLdL 25Nov06: I
   do not remember the reason for this...).

- Make fix-quotas and update-quotas call fix-bckp-quotas and
   update-bckp-quotas when a cluster-wide text quota file directory is
   defined.

   A possible reason for these observations: if the server has no root
   access to the cluster-wide directory, the programs fix-bckp-quotas
   and update-bckp-quotas, which overwrite the text quota files, will
   delete the symlinks in /etc/quotas/, exchanging them for new text
   files.

- Routine to check the text quota files: sort and unique to avoid
   duplicated lines.

- For the utility myrror-user:

   document the utility;

   define the set of languages: set langset = ( en pt );

   loop over the languages: use one, the othere, or both;

   define the location of the lock shell program;

   separate the text of the lock shell program;

   implement configurable exclusion lists.

