Ah, I remember that. I find that approach more cumbersome to use than mine. Note the ALTER cases can't tell you much about exactly how the relation has changed; you have to run comparisons of the pg_class rows manually, which is not very nice. I see this extension as a stopgap measure until we have real support for this in 9.5, per my patch.
I wish some similar interface for PL/pgSQL - json based interface is not PL/pgSQL friendly. But it can live in contrib as extension over your deparse interface - maybe as relatively simple SQL functions.
