gibbering funlets working on plugin type controller interfaces

plugin-type-controllers.php

<?php

interface PluginControllerInterface {
  /**
   * Retrieve plugin metadata for the named plugin of this type.
   */
  public function getPluginMetadata($name);
  /**
   * Retrieve plugin metadata for all plugins of this type.
   */
  public function getAllPluginMetadata();
}

interface PluginControllerContextualInterface extends DrupalPluginControllerInterface {
  public function setContext(DrupalContext $context);
}

interface PluginControllerSingleSlotInterface extends PluginControllerInterface {
  public function getPluginInstance($name);
}