Merged oacs-5-6 to HEAD. HEAD now installs and passes all core tests. There may still be some lingering problems due to my screwing up the oacs-5-6 branch earlier, I'll be looking into this later.
Changes for supporting postgresql 9.0: - Avoiding usage of SQL reserved keywords on plpsql functions (plpsql lexer and parser were reworked). - Fixing all those places on which FROM clause was automatically added by PG ( PG Config add_missing_from parameter was removed for this release of PG ). Many thanks to Tracy Adams and Jeff Lu for providing first version of the patches.