Simplify the class name finding and loading routines, since PSR-0 now handles them for us.

core/includes/Drupal/Database/Connection.php

core/includes/Drupal/Database/Database.php

core/includes/Drupal/Database/Driver/mysql/Connection.php

.../includes/Drupal/Database/Driver/mysql/DatabaseSchema.php

core/includes/Drupal/Database/Query/Insert.php

core/includes/Drupal/Database/Query/SelectExtender.php

core/includes/Drupal/Database/Query/Truncate.php

core/includes/bootstrap.inc

core/includes/database/mysql/install.inc

core/includes/database/pgsql/install.inc

core/includes/database/sqlite/install.inc

core/includes/install.core.inc

core/includes/install.inc

core/includes/registry.inc