Hotfix: Issue #2024093 by clemens.tolboom: Fixed entity-type-read and others are broken on big sites.

Additional comments in code, created _drush_entity_explode_options to replace similar function for bundle and field options

Added where clause for bundles in _drush_entity_id_list for drupal versions < 7, amended 'load list sql' property for these queries in _drush_entity_get_info

Added --load option to entity-read command so all returned entites can be loaded as well as just returning a list of ids

Removed labels from outputs using space separated lists, fixed entity-create to use json arrays of entities too, abstracted creation logic into helper function, related to [#1445154]

Added another simple test for --bundles option, added conditional to check entity type exists in drush_entity_type_read, removed newline char in _drush_entity_print