pgsql-server: Included is an example of using savepoints in a

Log Message:
-----------
Included is an example of using savepoints in a non-trivial example.

Giving examples in the SQL command reference is hard because we don't
have conditionals at the SQL level.

Gavin Sherry

Modified Files:
--------------
    pgsql-server/doc/src/sgml/ref:
        begin.sgml (r1.31 -> r1.32)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/ref/begin.sgml.diff?r1=1.31&r2=1.32)
        update.sgml (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/ref/update.sgml.diff?r1=1.29&r2=1.30)