Log Message:
-----------
Update GNU tar error code documentation.
Backpatch to 8.2.X.
Modified Files:
--------------
pgsql/doc/src/sgml:
backup.sgml (r2.99 -> r2.100)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/backup.sgml?r1=2.99&r2=2.100)