Log Message:
Changes 8.1.6:
* Improve handling of getaddrinfo() on AIX
  This fixes a problem with starting the statistics collector, among
  other things.
* Fix pg_restore to handle a tar-format backup that contains large
  objects (blobs) with comments
* Fix "failed to re-find parent key" errors in "VACUUM"
* Clean out "pg_internal.init" cache files during server restart
  This avoids a hazard that the cache files might contain stale data
  after PITR recovery.
* Fix race condition for truncation of a large relation across a
  gigabyte boundary by "VACUUM"
* Fix bug causing needless deadlock errors on row-level locks
* Fix bugs affecting multi-gigabyte hash indexes
* Fix possible deadlock in Windows signal handling
* Fix error when constructing an ARRAY[] made up of multiple empty
  elements
* Fix ecpg memory leak during connection
* Fix for Darwin (OS X) compilation
* to_number() and to_char(numeric) are now STABLE, not IMMUTABLE, for
  new initdb installs
  This is because lc_numeric can potentially change the output of
  these functions.
* Improve index usage of regular expressions that use parentheses
  This improves psql \d performance also.
* Update timezone database
  This affects Australian and Canadian daylight-savings rules in
  particular.