- Bumped version 0.2.0 -> 0.2.1
- Added WP_Library_Manager->has_libraries() to allow activate_plugin() to ignore non-managed plugins.
- Added WP_Library_Manager->has_loader() to complement has_libraries() (ignoring YAGNI)
- Added WP_Library_Manager->_get_plugin_file_from_slug() to support has_libraries(), has_loader() and future needs.