Make pg_options_to_table return NULL for an option with no value (Tom Lane)

Previously such cases would result in a server crash.

Fix memory leak at end of a GiST index scan (Tom Lane)

Commands that perform many separate GiST index scans, such as verification of a new GiST-based exclusion constraint on a table already containing many rows, could transiently require large amounts of memory due to this leak.

Fix explicit reference to pg_temp schema in CREATE TEMPORARY TABLE (Robert Haas)

This used to be allowed, but failed in 9.1.0.