#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

 - whitespaces at end of lines
 - indentation
 - control structure usage
 - whitespace in empty lines
 - phpdoc comment formatting

#175117 follow up patch by moshe weitzman: sanitize user name, remove t() because it might not be availabla and comment what is happening

#175117 by kbahey: developer improvement: include caller function name and user name in SQL queries for the query log when debug mode is turned on, so debugging gets easier

#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

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

- Patch #166205 by hswong3i: improved database compatibility of db_result().  Makes it work with DB2, Oracle, etc.

- Patch #159748 by pwolanin: db_fetch_array() returned different values depending on the database engine used.  Make the return value consistent across all supported database backends.

- Patch #149176 by chx, David et al: getting rid of the sequences table, using db_last_insert_id() instead of db_next_id().

- Patch #137479 by dww: added db_column_exits().  (Yay, the servers are snappy on Saturday evening.)

- Patch #98988 by Robert Douglass et al: db_result should return FALSE if no result was found.  Consistent with PHP's mysql_result.

- Patch #93945 by chx, jhm, et al: remove some session handler cruft from the mysqli database backend.

#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 #68926 by chx, jeremy, steven, eaton, webchick, amazon, neil, nedjo et al: an initial install system for Drupal core.

- Patch #47919 by Thomas: fixed various glitches with MySQLi's error handling and non-standard port support..