It is now possible for entity cache-aware controllers to reset only static cache

Previously the only option to reset an individual controller's static cache was to invoke the ::resetCache() method, unfortunately this also triggers a clear of the persistent cache. A new EntityCacheEntityControllerInterface was added, allowing entity cache-aware controllers to expose a ::resetStaticCache() method.

Before

  // Clear user static cache.
  $controller = entity_get_controller('user');
  $controller->resetCache(); // This also clears persistent cache!

After

  // Clear user static cache.
  $controller = entity_get_controller('user');
  $controller->resetStaticCache();