pgsql: Rename the internal structures of the CREATE TABLE (LIKE ...) fa

Rename the internal structures of the CREATE TABLE (LIKE ...) facility

The original implementation of this interpreted it as a kind of
"inheritance" facility and named all the internal structures
accordingly. This turned out to be very confusing, because it has
nothing to do with the INHERITS feature. So rename all the internal
parser infrastructure, update the comments, adjust the error messages,
and split up the regression tests.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/db49517c62750322fb2a37ff6324ecc00965e641

Modified Files
--------------
doc/src/sgml/ref/create_table.sgml | 4 +-
src/backend/nodes/copyfuncs.c | 10 +-
src/backend/nodes/equalfuncs.c | 6 +-
src/backend/nodes/outfuncs.c | 8 +-
src/backend/parser/gram.y | 10 +-
src/backend/parser/parse_utilcmd.c | 38 ++--
src/include/nodes/nodes.h | 2 +-
src/include/nodes/parsenodes.h | 12 +-
src/test/regress/expected/create_table_like.out | 222 ++++++++++++++++
src/test/regress/expected/inherit.out | 309 ++++-------------------
src/test/regress/expected/sanity_check.out | 3 +-
src/test/regress/output/misc.source | 3 +-
src/test/regress/parallel_schedule | 2 +-
src/test/regress/serial_schedule | 1 +
src/test/regress/sql/create_table_like.sql | 99 ++++++++
src/test/regress/sql/inherit.sql | 137 ++---------
16 files changed, 431 insertions(+), 435 deletions(-)