[evol] created display_artwork_frame() helper function and now use it in the welcome page + created a set/group tree view with it too
[fix] renamed 'technique' into more appropriate name 'artwork_support', and update schema and translations (Closes #4)
[evol] updated URLs in 'About' submenu
[evol] created a simple logon system, protected admin pages, and added a logon indicator/link (no user management yet, only a deadend entry in the menu if admin)
Initial version