customizing 'Orphaned images' container
add comment to settings.py
fixing custom template tag for retrieving settings

to display empty string instead of None
updating year in copyrights & spelling mistake
introducing hidden settings
adding default settings in process_custom_settings()
renaming hidden settings
adding comment to development settings
Merge pull request #2235 from aleksandra-tarkowska/trash_name_config

customizing 'Orphaned images' container