Issue #2433599 by Wim Leers: Ensure every (non-views) pager automatically associates a matching cache context

Issue #1912608 by Cottser, ckrina, jamesquinton, lauriii, jwilson3, mgifford, scaragucc' | criz: Update pagination markup for new CSS standards and improved accessibility.

Issue #2271251 by ParisLiakos, undertext, JeroenT, StevenPatz, tim.plunkett: Remove usages of watchdog() from non-form and non-controllers.

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #1289536 by ParisLiakos, RobLoach, Crell, larowlan, fgm, pounard, Pancho, dawehner, scor, tim.plunkett, alexpott, socketwench: Switch Watchdog to a PSR-3 logging framework.

Revert "Issue #1289536 by RobLoach, Crell, Pancho, pounard, socketwench, fgm, dawehner, scor, tim.plunkett, larowlan, ParisLiakos: Switch Watchdog to a PSR-3 logging framework."

This reverts commit ef250ba2.

Issue #1289536 by RobLoach, Crell, Pancho, pounard, socketwench, fgm, dawehner, scor, tim.plunkett, larowlan, ParisLiakos: Switch Watchdog to a PSR-3 logging framework.

Issue #1614186 by RobLoach, tim.plunkett, msonnabaum, Crell, jhodgdon, Niklas Fiekas: Update coding standards for using 'native' PHP classes like stdClass in namespaced code.

Issue #1711070 by kid_icarus, tim.plunkett, xjm, droplet, zendoodles and cam8001: Convert tests to use ::$modules property instead of parent::setUp($modules).

Issue #41595 follow-up by BTMash, scor: Fixed pager tests so they now work from Drupal sub-directory installs.