inline_entity_form 8.x-1.0-alpha2

Changes since 8.x-1.0-alpha1:

• Rename the multiple widget to the complex widget (as decided in #2532810).
• #2568255 by dbolinovski: Entity level validation constraints in multivalue IEF
• #2560915 by floretan: Buttons disappear after removing entity
• #2581727 by slashrsm: "Calling getComponent() on null" when trying to delete entity
• #2577651 by slashrsm: Notice: Undefined index: target_bundles in Drupal\inline_entity_form\Plugin\Field\FieldWidget\InlineEntityFormSimple::isApplicable()
• #2558567 by slashrsm: Prevent potential notice in \Drupal\inline_entity_form\Element\InlineEntityForm::recurseAttachMainSubmit()
• Widgets must not access ->settings directly because the defaults are not merged in.
• #2508107 by slashrsm, floretan: Port "Single" IEF field widget to D8
• Remove the unported TaxonomyTermInlineEntityFormHandler.
• Remove example for non-existent hook_inline_entity_form_settings_alter().
• Remove inline_entity_form_get_controller().
• #2401171 by bojanz, joelpittet: Turn off table drag when only one value is available.
• #2056139: Port the 'Allow users to add new entity' setting.
• #2538576: Undefined variable: entities_count in InlineEntityFormMultiple
• Separate the settings specific to the 'Multiple' widget from the generic settings.
• The target_bundles setting isn't guaranteed to be keyed by the bundle name.
• Fix #states in widget settings.
• #2534320 by dawehner, floretan: Cannot create entities for types without bundles
• Use entity_get_form_display() to prevent a crash when the child entity type has no form display.
• #2529114 by woprrr, bojanz: Remove the "delete_references" option and functionality
• #2531574 by webflo: Use field formatter for table fields
• Use StringTranslationTrait in NodeInlineEntityFormHandler
• Issues #1876652 and #2472769 by webflo: Weight delta only supports ordering of 50 items
• #2324901 and #2472769 by jan.stoeckler: Add callback field type for theme_inline_entity_form_entity_table
• #2528998 by slashrsm: Chase core: Validation of inline entities