yched

Put field data cache back on, for fair benchmarks

Merge branch 'plugins-next' into plugins-field-api-next

Conflicts:
core/includes/bootstrap.inc
core/lib/Drupal/Component/Plugin/Discovery/StaticDiscovery.php
core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php
core/lib/Drupal/Component/Plugin/Kernel/PluginKernel.php
core/lib/Drupal/Core/Plugin/Discovery/ConfigDiscovery.php
core/modules/field/field.api.php
core/modules/field/field.attach.inc
core/modules/field/field.module
core/modules/field/field.multilingual.inc
core/modules/field/modules/field_sql_storage/field_sql_storage.module
core/modules/field/modules/text/text.module
core/modules/field/tests/field.test
core/modules/field/tests/field_test.storage.inc
core/modules/field_ui/field_ui.api.php
core/modules/simpletest/simpletest.info
core/modules/taxonomy/taxonomy.module
core/modules/taxonomy/taxonomy.test
profiles/standard/standard.install

Issue #1442886 by pdrake: Fixed fatal error "failed opening theme.inc" in some edge cases.

Issue #1167004 followup by DeFr, markus_petrux