#219380 by chx: bring back support for queries without WHERE clause to db_rewrite_sql() (regression)

#151910 by chx: support subqueries in db_rewrite_sql() - now that we use subqueries even in core, this was critical

#198856 by hswong3i: Fix some incorrect use of %s for table name escaping, implement better security checks

#168315 by schuyler1d: previous active database name was not consistently returned in db_set_active()

#178523 by scor, JirkaRybka, keith.smith: user facing errors should contain text for users, not text for developers; still keeping some debug information, if display_errors is turned on on the server

#182728 by gpk: more accurante phpdoc for db_rewrite_sql() and _db_rewrite_sql(), mentioning table aliases used

#141727 by merlinofchaos, dvessel, sun: restore themeability support for maintenance pages (regression)

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

- Patch #169982 by moshe, eaton, bjaspan, nedjo, yched, et al: missing feature from schema API: load/save records based upon schema.

#167284 by Heine and pwolanin: proper field type placeholders in IN() queries, setting a best practice to avoid vulnerabilities

#168812 by webchick and pwolanin: in case we have a database error, trace it back to the original database function call, so we can provide a more accurate error message for DB errors

#155282 by Jose A Reyero: apply db_rewrite_sql() to the block listing query to allow for multilingual blocks

#150210 by bjaspan and Frando: explicit table names for create table statements and fixing a schema referencing bug

- Patch #99011 by merlinofchaos: remove sites/default/settings.php and ship with sites/default/default.settings.php.

#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.

fixes 57406 too