- #40515: Ensure UTF-8 character set on the database side (and include upgrade path for incorrectly set up databases)

  - When user #1 creates an account (we can assume this happens only once), system.module's schema version is set to the latest availiable.
  - system_get_files_database() now includes a 'schema_version' child of each file object.
  - That new information is re-saved when Drupal re-populates the system table.
  - An array of newly-enabled modules is built, module_list() is reloaded, and the schema versions of each newly-enabled module are set to the most recent availiable. If the schema version is already set (presumably from a previous installation) it is not changed.

- Patch #40303 by Cvbge: drop old columns for PostgreSQL and fixed some PostgreSQL problems in the update script.

  TODO:
  + The contact.module was broken; a new patch for contact.module is needed.
  + Documentation is needed.
  + The most important modules need to be updated ASAP.

- Patch #29051 by mathias: made the update.php script work when Drupal is installed in a subdirectory.

  PHP warning.