Fix message typo.
Fix broken pg_dump for 9.0 and 9.1 caused by the MV patch.

Per report and suggestion from Bernd Helmle
Add docs for pg_matviews, which were missed in the initial MV commit.
WAL-log the extension of a new empty MV heap which is being populated.

This page with no tuples is used to distinguish an MV containing a
zero-row resultset of its backing query from an MV which has not
been populated by its backing query.  Unless WAL-logged, recovery
and hot standby don't work correctly with what should be an empty
but scannable materialized view.

Fixes bugs reported by Fujii Masao in testing MVs on hot standby.
Fix missing #include in commands/matview.h.

It needs parsenodes.h to be compilable regardless of previous headers.
Adjust nls.mk for split out of wait_error.c
Code beautification for object-access hook machinery.

KaiGai Kohei
Add fe_memutils.c to nls.mk where used
Arrange to cache FdwRoutine structs in foreign tables' relcache entries.

This saves several catalog lookups per reference.  It's not all that
exciting right now, because we'd managed to minimize the number of places
that need to fetch the data; but the upcoming writable-foreign-tables patch
needs this info in a lot more places.