Issue #3256524 by mondrake: [11.x] Adjust Database API to remove deprecated Drupal 10 code in Drupal 11

Issue #3405976 by alexpott, jrglasgow, fago, catch, mondrake, solideogloria, mglaman, Driskell, derickr, longwave, Mile23, YesCT, daffie: Transaction autocommit during shutdown relies on unreliable object destruction order (xdebug 3.3+ enabled)

This reverts commit 70b607c3.

Issue #2932518 by kim.pepper, joachim, bradjones1, voleger, cliddell, gapple, Xano, andregp, andypost, neclimdul, rpayanm, Hardik_Patel_12, NWOM, smustgrave, dawehner, alexpott, daffie, larowlan, Berdir, mstrelan, xjm, dagmar: Deprecate watchdog_exception

Issue #2924781 by osman, yogeshmpawar, zaporylie, mfernea: Missing @var annotation for scalars that do not provide default values

Issue #2801899 by shashikant_chauhan, daffie, axel.rutz: Rename Drupal\Core\Database\Connection::rollback() to Drupal\Core\Database\Connection::rollBack()

Issue #2719695 by alexpott, Mile23: Fix 'Drupal.Classes.ClassDeclaration.CloseBraceAfterBody' coding standard

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #1897058 by disasm, rteijeiro: Replace "boolean" with "bool" when used as param/return/var type

Issue #2100329 by cosmicdreams: Use \Drupal instead of Drupal to make IDEs and static code analyse tools happy.

Issue #843114 by sun, quicksketch, Berdir, c960657, Crell: Fixed DatabaseConnection::__construct() and DatabaseConnection_mysql()::__construct() leaks  (Too many connections).

Initial move and rename of database classes to PSR-0 namespaces.  So far only MySQL has been converted.