Log Message:
Changes 8.1.9:
* Support explicit placement of the temporary-table schema within
  search_path, and disable searching it for functions and operators
* "/contrib/tsearch2" crash fixes
* Require "COMMIT PREPARED" to be executed in the same database as
  the transaction was prepared in
* Fix potential-data-corruption bug in how "VACUUM FULL" handles
  "UPDATE" chains
* Planner fixes, including improving outer join and bitmap scan
  selection logic
* Fix PANIC during enlargement of a hash index (bug introduced in
  8.1.6)
* Fix POSIX-style timezone specs to follow new USA DST rules