Issue #3081145 by Berdir, andypost, longwave, catch, tim.plunkett, larowlan: Remove BC layers in the Plugin component

Revert "Issue #2852463 by mikelutz, tim.plunkett, heddn, xjm, MegaChriz, joachim, phenaproxima, dawehner, benjifisher: Create a trait to implement \Drupal\Component\Plugin\ConfigurableInterface"

This reverts commit 109dfd58.

Issue #2852463 by mikelutz, tim.plunkett, heddn, xjm, MegaChriz, joachim, phenaproxima, dawehner, benjifisher: Create a trait to implement \Drupal\Component\Plugin\ConfigurableInterface

Issue #2946122 by mikelutz, heddn, tim.plunkett, phenaproxima, alexpott, joelpittet, MegaChriz, joachim, xjm: Deprecate ConfigurablePluginInterface and replace with an interface that doesn't extend DependentPluginInterface

Revert "Issue #2946122 by mikelutz, heddn, tim.plunkett, phenaproxima, alexpott, MegaChriz, joachim: Deprecate ConfigurablePluginInterface and replace with an interface that doesn't extend DependentPluginInterface"

This reverts commit b1f49624.

Issue #2946122 by mikelutz, heddn, tim.plunkett, phenaproxima, alexpott, MegaChriz, joachim: Deprecate ConfigurablePluginInterface and replace with an interface that doesn't extend DependentPluginInterface

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

Issue #2851635 by tim.plunkett, alexpott, dawehner: DefaultSingleLazyPluginCollection retains stale instance IDs

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

Issue #2248151 by tim.plunkett, xjm, alexpott: Configurable plugins can not control instance-specific config dependencies.

Issue #2062573 by claudiu.cristea, tim.plunkett, Xano: Change notice: Add method defaultConfiguration() in ConfigurablePluginInterface.