Merge branch 'master' into fdw_core

diff --cc doc/src/sgml/catalogs.sgml
Simple merge

diff --cc src/backend/commands/explain.c
Simple merge

diff --cc src/backend/nodes/copyfuncs.c
Simple merge

diff --cc src/backend/nodes/outfuncs.c
Simple merge

diff --cc src/backend/optimizer/path/costsize.c
Simple merge

diff --cc src/backend/optimizer/plan/createplan.c
Simple merge

diff --cc src/backend/optimizer/plan/setrefs.c
Simple merge

diff --cc src/backend/optimizer/plan/subselect.c
Simple merge

diff --cc src/backend/optimizer/util/pathnode.c
Simple merge

diff --cc src/include/catalog/pg_proc.h
Simple merge

diff --cc src/include/nodes/execnodes.h
Simple merge

diff --cc src/include/nodes/plannodes.h
Simple merge

diff --cc src/include/nodes/relation.h
Simple merge

diff --cc src/include/optimizer/cost.h
Simple merge

diff --cc src/include/optimizer/pathnode.h
Simple merge