new db schema and data in sql folder
added users attribute started_at
us40418: Dropdown changed to have a default value. It can be enabled/disabled, selected value can be easily changed from outside. An empty item was added to the option-list
us40420: Filtrable component added.
us40420: Filter component added. Observer modified to fire source as well. Test view added. Css added.
us40420: Divs' IDs added, minor changes in CSS