#76819 by smsimms and sammys. Move part of the sql rewriting down into the database abstraction layer and add extra rewriting needed only for Postgres.

- Patch #88287 by asimmonds, dww et al: installer doesn't support modules outside root/modules directory.  Critical bugfix.

- Patch #75395 by chx, merlin and natrak: incorporate node access arbitrator into node.module.  Critical bugfix.

- Patch #90128 by gotheric and chx: worked around incompatible change in MySQL 5.0.13.  Actually improves portability with databases like Oracle.  Critical bugfix as it prevented search indexing from working.

#24023 by chx. Allow multiple select options with the same value and implement it for taxonomy selection.