Log Message:
-----------
CVS NULL Documentation
Clearify documentation of CVS's output of NULL values, per suggestion
from Magnus.
Backpatch to 8.4.X.
Modified Files:
--------------
pgsql/doc/src/sgml/ref:
copy.sgml (r1.87 -> r1.88)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/copy.sgml?r1=1.87&r2=1.88)