REASSIGN OWNED: consider grants on tablespaces, too

Apparently this was considered in the original code (see commit
cec3b0a9) but I failed to notice that such entries would always be
skipped by the database check at the start of the loop.

Per bugs #7578 by Nikolay, #6116 by tushar.qa@gmail.com.
Avoid planner crash/Assert failure with joins to unflattened subqueries.

examine_simple_variable supposed that any RTE_SUBQUERY rel it gets pointed
at must have been planned already.  However, this isn't a safe assumption
because we must do selectivity estimation while generating indexscan paths,
and that code might look at join clauses involving a rel that the loop in
set_base_rel_sizes() hasn't reached yet.  The simplest fix is to play dumb
in such a situation, that is give up trying to extract any stats for the
Var.  This could possibly be improved by making a separate pass over the
RTE list to plan each unflattened subquery before we start the main
planning work --- but that would be pretty invasive and it doesn't seem
worth it, for now at least.  (We couldn't just break set_base_rel_sizes()
into two loops: the prescan would need to handle all subquery rels in the
query, not only those in the current join subproblem.)

This bug was introduced in commit 1cb108efb0e60d87e4adec38e7636b6e8efbeb57,
although I think that subsequent changes may have exposed it more than it
was originally.  Per bug #7580 from Maxim Boguk.
refactor ALTER some-obj SET OWNER implementation

Remove duplicate implementation of catalog munging and miscellaneous
privilege and consistency checks.  Instead rely on already existing data
in objectaddress.c to do the work.

Author: KaiGai Kohei
Tweaked by me
Reviewed by Robert Haas
Support CREATE SCHEMA IF NOT EXISTS.

Per discussion, schema-element subcommands are not allowed together with
this option, since it's not very obvious what should happen to the element
objects.

Fabrízio de Royes Mello
Fix typo in comment, and reword it slightly while we're at it.
Non Workon Support for CHECK and DEFAULT clauses.
Add support for table level constraints rewriting (not tested yet).
Fix permissions explanations in CREATE DATABASE and CREATE SCHEMA docs.

These reference pages still claimed that you have to be superuser to create
a database or schema owned by a different role.  That was true before 8.1,
but it was changed in commits aa1110624c08298393dfce996f7b21809d98d3fd and
f91370cd2faf1fd35a1ac74d84652a85ed841919 to allow assignment of ownership
to any role you are a member of.  However, at the time we were thinking of
that primarily as a change to the ALTER OWNER rules, so the need to touch
these two CREATE ref pages got missed.
Fix parse location tracking for lists that can be empty.

The previous coding of the YYLLOC_DEFAULT macro behaved strangely for empty
productions, assigning the previous nonterminal's location as the parse
location of the result.  The usefulness of that was (at best) debatable
already, but the real problem is that in list-generating nonterminals like
	OptFooList: /* EMPTY */ { ... } | OptFooList Foo { ... } ;
the initially-identified location would get copied up, so that even a
nonempty list would be given a bogus parse location.  Document how to work
around that, and do so for OptSchemaEltList, so that the error condition
just added for CREATE SCHEMA IF NOT EXISTS produces a sane error cursor.
So far as I can tell, there are currently no other cases where the
situation arises, so we don't need other instances of this coding yet.
Make CREATE AGGREGATE complain if the initcond is invalid for the datatype.

The initial transition value is stored as a text string and not fed to the
transition type's input function until runtime (so that values such as
"now" don't get frozen at creation time).  Previously, CREATE AGGREGATE
didn't do anything with it but that, which meant that even erroneous values
would be accepted and not complained of until the aggregate is used.  This
seems unhelpful, and it's confused at least one user, as in Rhys Stewart's
recent report.  It seems worth taking a few more cycles to invoke the input
function and verify that the value is acceptable.  We can't do this if the
transition type is polymorphic, but in normal aggregates we know the actual
transition type so we can call the right input function.
Remove redundant code for getnameinfo() replacement

Our getnameinfo() replacement implementation in getaddrinfo.c failed
unless NI_NUMERICHOST and NI_NUMERICSERV were given as flags, because
it doesn't resolve host names, only numeric IPs.  But per standard,
when those flags are not given, an implementation can still degrade to
not returning host names, so this restriction is unnecessary.  When we
remove it, we can eliminate some code in postmaster.c that apparently
tried to work around that.
PL/pgSQL: rename gram.y to pl_gram.y

This makes the naming inside plpgsql consistent and distinguishes the
file from the backend's gram.y file.  It will also allow easier
refactoring of the bison make rules later on.
getnameinfo_unix has to be taught not to insist on NI_NUMERIC flags, too.

Per testing of previous patch.
Add support for CREATE TABLE OF
Merge branch 'master' of https://github.com/postgres/postgres into evt_add_info