OO inheritance implementation

I'm trying to figure out how to implement the behaviour of returning all
subclass fields. i.e. the "SELECT **" behaviour talked about in the
past.

What I'm thinking is that transformTargetList will do the same thing as
per "*" except that it will set another flag "and_the_rest".

plan_inherit_queries will then notice the flag and then expand the
target list as per each sub-class.

This seems to be the way to do it as far as I can see. It doesn't seem
ideal is so far as "*" and "**" would not be handled in the same place,
but since currently "*" and the breaking up of inheritance queries into
an append plan happen in different places, this seems inevitable unless
one were to totally rearrange the order things are done in the backend.

Any comments?