Log Message:
-----------
Add description that WAL files used during backup have to be archived
before you are done.
Modified Files:
--------------
pgsql/doc/src/sgml:
backup.sgml (r2.62 -> r2.63)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/backup.sgml.diff?r1=2.62&r2=2.63)