* -Make oid use oidin/oidout not int4in/int4out in pg_type.h (Tom)

* Improve Subplan list handling

* Allow Subplans to use efficient joins(hash, merge) with upper variable

[subquery]

* -use fmgr_info()/fmgr_faddr() instead of fmgr() calls in high-traffic

places, like GROUP BY, UNIQUE, index processing, etc.

* improve dynamic memory allocation by introducing tuple-context memory