[HACKERS] new relkind for view

[Zeugswetter Andreas SB]

> > 2. The executor complains if a DELETE or
> > INSERT references a view.

I think this is for new todo items:
create insert, update and delete rules for simple one table views
change elog for complex view ins|upd|del to "cannot {ins|upd|del}
[into|from] complex view without an on {ins|upd|del} rule"
add the functionality for "with check option" clause of create view

Andreas