Smaller access privilege changes

Since there is no plan yet how to do a wholesale overhaul of the ACL
system, I'd like to stick a few improvements into the current
implementation:

* Make DELETE distinct from UPDATE privilege

* rename the internal representation: s = select, i = insert, u = update,
d = delete, R = rules

* LOCK > AccessShare will require UPDATE or DELETE. This is not a change
in effect.

* Sequence nextval and setval will require UPDATE; DELETE won't do any
longer.

* COPY FROM will require INSERT privilege. It used to require
UPDATE/DELETE, it think that is not correct..

* INSERT (the command) will require INSERT privilege. UPDATE/DELETE won't
do any longer. (Why was this there?)

* Implement SQL REFERENCES privilege: grant references on A to B will
allow user B to create a foreign key referencing table A as primary key.

I'd also like to create a regression test. That will require creating
some global users and groups in the installation where the test runs. I
think as long as we name them "regressuser1", "regressgroup2", etc. this
won't harm anyone.

Comments?

--
Peter Eisentraut peter_e(at)gmx(dot)net http://funkturm.homeip.net/~peter