pgsql: Remove the Query structure from the executor's API.

Log Message:
-----------
Remove the Query structure from the executor's API. This allows us to stop
storing mostly-redundant Query trees in prepared statements, portals, etc.
To replace Query, a new node type called PlannedStmt is inserted by the
planner at the top of a completed plan tree; this carries just the fields of
Query that are still needed at runtime. The statement lists kept in portals
etc. now consist of intermixed PlannedStmt and bare utility-statement nodes
--- no Query. This incidentally allows us to remove some fields from Query
and Plan nodes that shouldn't have been there in the first place.

Still to do: simplify the execution-time range table; at the moment the
range table passed to the executor still contains Query trees for subqueries.

initdb forced due to change of stored rules.

Modified Files:
--------------
pgsql/src/backend/commands:
copy.c (r1.275 -> r1.276)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/copy.c.diff?r1=1.275&r2=1.276)
explain.c (r1.155 -> r1.156)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/explain.c.diff?r1=1.155&r2=1.156)
portalcmds.c (r1.60 -> r1.61)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/portalcmds.c.diff?r1=1.60&r2=1.61)
prepare.c (r1.68 -> r1.69)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/prepare.c.diff?r1=1.68&r2=1.69)
pgsql/src/backend/executor:
execMain.c (r1.286 -> r1.287)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execMain.c.diff?r1=1.286&r2=1.287)
execUtils.c (r1.144 -> r1.145)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execUtils.c.diff?r1=1.144&r2=1.145)
functions.c (r1.110 -> r1.111)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/functions.c.diff?r1=1.110&r2=1.111)
spi.c (r1.169 -> r1.170)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/spi.c.diff?r1=1.169&r2=1.170)
pgsql/src/backend/nodes:
copyfuncs.c (r1.366 -> r1.367)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/copyfuncs.c.diff?r1=1.366&r2=1.367)
equalfuncs.c (r1.298 -> r1.299)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/equalfuncs.c.diff?r1=1.298&r2=1.299)
outfuncs.c (r1.299 -> r1.300)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/outfuncs.c.diff?r1=1.299&r2=1.300)
readfuncs.c (r1.202 -> r1.203)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/readfuncs.c.diff?r1=1.202&r2=1.203)
pgsql/src/backend/optimizer/path:
allpaths.c (r1.159 -> r1.160)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/allpaths.c.diff?r1=1.159&r2=1.160)
pgsql/src/backend/optimizer/plan:
planagg.c (r1.27 -> r1.28)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/plan/planagg.c.diff?r1=1.27&r2=1.28)
planner.c (r1.213 -> r1.214)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/plan/planner.c.diff?r1=1.213&r2=1.214)
pgsql/src/backend/parser:
analyze.c (r1.360 -> r1.361)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/analyze.c.diff?r1=1.360&r2=1.361)
gram.y (r2.579 -> r2.580)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.579&r2=2.580)
pgsql/src/backend/tcop:
postgres.c (r1.524 -> r1.525)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/postgres.c.diff?r1=1.524&r2=1.525)
pquery.c (r1.113 -> r1.114)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/pquery.c.diff?r1=1.113&r2=1.114)
utility.c (r1.272 -> r1.273)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/utility.c.diff?r1=1.272&r2=1.273)
pgsql/src/backend/utils/mmgr:
portalmem.c (r1.98 -> r1.99)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mmgr/portalmem.c.diff?r1=1.98&r2=1.99)
pgsql/src/include/catalog:
catversion.h (r1.387 -> r1.388)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.387&r2=1.388)
pgsql/src/include/commands:
portalcmds.h (r1.20 -> r1.21)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/portalcmds.h.diff?r1=1.20&r2=1.21)
prepare.h (r1.23 -> r1.24)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/prepare.h.diff?r1=1.23&r2=1.24)
pgsql/src/include/executor:
execdesc.h (r1.33 -> r1.34)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/execdesc.h.diff?r1=1.33&r2=1.34)
executor.h (r1.136 -> r1.137)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/executor.h.diff?r1=1.136&r2=1.137)
spi_priv.h (r1.26 -> r1.27)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/spi_priv.h.diff?r1=1.26&r2=1.27)
pgsql/src/include/nodes:
execnodes.h (r1.167 -> r1.168)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/execnodes.h.diff?r1=1.167&r2=1.168)
nodes.h (r1.195 -> r1.196)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/nodes.h.diff?r1=1.195&r2=1.196)
parsenodes.h (r1.340 -> r1.341)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/parsenodes.h.diff?r1=1.340&r2=1.341)
plannodes.h (r1.90 -> r1.91)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/plannodes.h.diff?r1=1.90&r2=1.91)
primnodes.h (r1.125 -> r1.126)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/primnodes.h.diff?r1=1.125&r2=1.126)
relation.h (r1.136 -> r1.137)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/relation.h.diff?r1=1.136&r2=1.137)
pgsql/src/include/optimizer:
planner.h (r1.37 -> r1.38)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/planner.h.diff?r1=1.37&r2=1.38)
pgsql/src/include/tcop:
pquery.h (r1.40 -> r1.41)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/tcop/pquery.h.diff?r1=1.40&r2=1.41)
tcopprot.h (r1.86 -> r1.87)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/tcop/tcopprot.h.diff?r1=1.86&r2=1.87)
utility.h (r1.30 -> r1.31)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/tcop/utility.h.diff?r1=1.30&r2=1.31)
pgsql/src/include/utils:
portal.h (r1.72 -> r1.73)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/portal.h.diff?r1=1.72&r2=1.73)
pgsql/src/pl/plpgsql/src:
pl_exec.c (r1.188 -> r1.189)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_exec.c.diff?r1=1.188&r2=1.189)