Log Message:
Changes 9.1.2:
* Fix bugs in information_schema.referential_constraints view
* Correct collations for citext columns and indexes
* Prevent possible crash when joining to a scalar function
* Prevent transitory data corruption of GIN indexes after a crash
* Prevent data corruption on TOAST columns when copying data
* Fix failures during hot standby startup
* Correct another "variable not found in subplan target list" bug
* Fix bug with sorting on aggregate expressions in windowing functions
* Multiple bug fixes for pg_upgrade
* Change Foreign Key creation order to better support self-referential keys
* Multiple bug fixes to CREATE EXTENSION
* Ensure that function return type and data returned from PL/perl agree
* Ensure that PL/perl strings are always UTF-8
* Assorted bug fixes for various Extensions
* Updates to the time zone database, particularly to CST6