pg_upgrade:  remove support for 8.3 old clusters

This trims down the code, and is in preparation for hardening pg_upgrade
against auto-oid assignment.
revert "Throw error for ALTER TABLE RESET of an invalid option"

Reverts commits 73d78e11a0f7183c80b93eefbbb6026fe9664015 and
b0488e5c4fbfdce8acc989bdc17d9f0ec09ac281.  Also reverts pg_upgrade
changes.
pg_upgrade docs:  update docs for 8.3 support removal
pg_upgrade:  use CTE query rather than temp table

Now that 8.3 is not supported, we can use a CTE and not temp tables.
This allows for auto-oid assignment protection in a future patch.
rename macro isTempOrToastNamespace to isTempOrTempToastNamespace

Done for clarity
pg_upgrade:  prevent automatic oid assignment

Prevent automatic oid assignment when in binary upgrade mode.  Also
throw an error when contrib/pg_upgrade_support functions are called when
not in binary upgrade mode.

This prevent automatically-assigned oids from conflicting with later
pre-assigned oids coming from the old cluster.  It also makes sure oids
are preserved in call important cases.
merge master