Misc stuff for main commit

Simplify explain output

Remove obsolete comment on explain output

Justify previous subselect.c comments

wCTE plan list comments updated

Remove over-explanation of param plans in executor

Consolidate remarks on child plans

Don't append resultrelation where unnecessary

Remove comment regarding setrefs.c + excluded RTE

Much better explanation of auxiliary plan concept in comments

Provisional: refactor costing stuff

Whitespace fix

Assert in explain.c

Simplify HeapTupleSelfUpdated handling

Statement triggers: insert, update, update, insert

Conclusively locked, update qual stuff

Junk filter diff minimization

ExecInsertIndexTuples() tweaks
EXCLUDED stuff

Better comments on contract between EPQ + ExcludedExpr

Not RTE, INNER_VAR varno

Comments on RTE lifetime within analyze.c
Fix statement trigger test regression
Doc stuff

update ddl sgml remarks

New statement-level trigger behavior