Names of view select rules

Currently, the name of the ON SELECT rule for a view is defined to be
'_RET' || viewname
truncated if necessary to fit in a NAME.

I've just committed fixes to make rule names be per-relation instead
of global, and it occurs to me that we could now get rid of this
convention. The select rule name could be the same for all views ---
"_RETURN", say. This would simplify life in a number of places.

A quick look at psql, pgaccess, etc suggests that a lot of places know
that view select rule names begin with _RET, but not that many are
dependent on the rest of it. So I think this wouldn't break clients
too badly.

Any thoughts pro or con? I'm leaning towards changing it, but could be
persuaded to leave well enough alone.

regards, tom lane