pgsql: Regression tests for large objects.

Log Message:
-----------
Regression tests for large objects. Patch from Jeremy Drake.

Modified Files:
--------------
    pgsql/src/test/regress:
        parallel_schedule (r1.36 -> r1.37)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/parallel_schedule.diff?r1=1.36&r2=1.37)
        serial_schedule (r1.34 -> r1.35)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/serial_schedule.diff?r1=1.34&r2=1.35)

Added Files:
-----------
    pgsql/src/test/regress/input:
        largeobject.source (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/input/largeobject.source?rev=1.1&content-type=text/x-cvsweb-markup)
    pgsql/src/test/regress/output:
        largeobject.source (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/output/largeobject.source?rev=1.1&content-type=text/x-cvsweb-markup)