Обсуждение: pgsql: Revert patch pending more discussion: Disallow changing DEFAULT

Log Message:
-----------
Revert patch pending more discussion:

Disallow changing DEFAULT expression of a SERIAL column.

Modified Files:
--------------
    pgsql/doc:
        TODO (r1.1817 -> r1.1818)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1817&r2=1.1818)
    pgsql/doc/src/FAQ:
        TODO.html (r1.320 -> r1.321)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html.diff?r1=1.320&r2=1.321)
    pgsql/src/backend/catalog:
        dependency.c (r1.52 -> r1.53)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/dependency.c.diff?r1=1.52&r2=1.53)
        heap.c (r1.297 -> r1.298)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/heap.c.diff?r1=1.297&r2=1.298)
    pgsql/src/backend/commands:
        tablecmds.c (r1.182 -> r1.183)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c.diff?r1=1.182&r2=1.183)
    pgsql/src/include/catalog:
        dependency.h (r1.22 -> r1.23)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/dependency.h.diff?r1=1.22&r2=1.23)
        heap.h (r1.79 -> r1.80)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/heap.h.diff?r1=1.79&r2=1.80)