Make scald_render_multiple compatible with Entity API

Entity view function "scald_render_multiple" should return array keyed by entity type, and then another nested array keyed by entity id.

return array(
  'scald_atom' => array(
    12 => array(/*...render array for scald_atom with sid 12...*/),
    13 => array(/*...render array for scald_atom with sid 13...*/),
    14 => array(/*...render array for scald_atom with sid 14...*/),
  ),
);

I know that EntityAPIControllerInterface::view() is not telling you this, but have a look at EntityAPIController::view() of DrupalCommerceEntityController::view().

Scenario of one of possible bugs:
1. Create view for scald atoms.
2. Choose "Rendered entity" as format to show
3. Choose any format you like
4. See no results shown

See entity_views_plugin_row_entity_view::pre_render() and entity_views_plugin_row_entity_view::render() for more details about views integration bug.