#178581 by lot of contributors: opt-in for update module on install and update to avoid any privacy concerns

#185126 by moshe weitzman, David Strauss, bjaspan and JirkaRybka: improve index on system table for better database performance

#184867 by deekayen, catch and keith.smith: fix some spelling errors in our source code and messages printed

#181088 by fajerstarter, catch and JirkaRybka: rename 'access control' to 'permissions' for usability reasons

#181758 by webernet: move cache_block creation to update_fix_d6_requirements() to avoid warnings about the nonexistent table through the update process

- Patch #150245 by webchick, bjaspan, ralf, Arancaytar et al: move the .schema files into .install files to prevent mistakes.

#162432 by bjaspan and chx: serial columns need their keys defined in db_change_field() and friends in MySQL

#173982 follow up patch by webernet: the profile table might not exist, so we need to check for its existance before updating it

#173982 by pwolanin and chx: fix schema inconsistencies between a fresh Drupal 6 install and a Drupal 5 upgraded to Drupal 6

#173314 by drewish: mark previously uploaded files as permanent, so they will not be deleted after an upgrade

#111127 rollback by chx, slightly extended: roll back node_load cache, it needs more thought and discussion, so postponed until at least Drupal 7

#149567 by chx and meba: set install_task variable to 'done' on update, so installer cannot be run on Drupal 6 on an upgraded site

#170638 by JirkaRybka and chx: move update access variable to settings.php, so we can check whether it is wide open, and we have one place for settings

#111127 by chx: cache node_load(), so heavy operations loading data from external sources and only invoked once (note that you should do everything dynamic in the view op, not the load op)

#165141 by hswong3i: move literal values out of some core queries to support cross-database compatibility (ie. better SQL parsing and altering options)

- Patch #163191 by hswong3i: removed db_num_rows() for compatibility with Oracle and DB2.  Also a performance improvement. (Correct version this time.)

- Patch #163191 by hswong3i: removed db_num_rows() for compatibility with Oracle and DB2.  Also a performance improvement.

#165141 by hswong3i: when inserting values into VARCHAR fields, we should use quotes, even if the values are numbers

  Woot, woot! :)