Added initial EntityEmbedDisplay and EntityEmbedDefaultDisplay classes to control the display of the embedded entity.
Added EntityEmbedDisplay plugin, plugin interface, and plugin manager.
Added EntityEmbedDisplayManager::getDefinitionsByEntity().
Added entity_embed.api.php.
Merge branch '8.x-1.x' into embed-display
Doc cleanups.
Added entity embed display plugins for entity_reference, file, and image field formatters.
Merge branch '8.x-1.x' into embed-display

Conflicts:
	src/Plugin/Filter/EntityEmbedFilter.php
Removed file and image field formatters. Too many bugs in the system right now.
Ensure that the fake field definitions always get a unique name by using the post_render_cache placeholder token.
Re-adding file and image formatter embed plugins since they work now\!
Merge branch '8.x-1.x' into embed-display

Conflicts:
	src/Plugin/Filter/EntityEmbedFilter.php
Fixup documentation in src/Plugin/Derivative/FieldFormatter.php.
Fixed variable not changed from $field to $definition.
Moved checking display annotation 'types' value to it's own method for more easier overridding of EntityEmbedDisplayBase::access().
Added a getFormatter() helper method on FieldFormatterEntityEmbedDisplayBase.
Integrate the EntityEmbedPlugin type with PluginFormInterface. Supports field formatter settings forms.
Support defaultConfiguration() for field formatter plugins.
Removed unnecessary use statements for classes in same exact namespace.
Added EntityEmbedDefaultDisplay::buildConfigurationForm().