user can upload many images of his gadgets
final version for list mode collection representation
added contenflow plugin for real cover flow mode,
x-editable for in-place editing of gadget title,
welcome page with application description,
refactored buttons with new button helper for styling buttons with icons,
improved mode selector with highlighting of current view mode,
refactored in-view javascript to use in separate files,
destroy gadgets with dependent photos,
all tests pass.