 Ref #19: add thumbnail image placeholders
 Ref #19: add thumbnail image placeholders

smargovsky/uw-ui-toolkit,nblair/uw-ui-toolkit,smargovsky/uw-ui-toolkit,nblair/uw-ui-toolkit,smargovsky/uw-ui-toolkit,UWMadisonUcomm/uw-ui-toolkit,UWMadisonUcomm/uw-ui-toolkit,timlevett/uw-ui-toolkit,timlevett/uw-ui-toolkit,nblair/uw-ui-toolkit,UWMadisonUcomm/uw-ui-toolkit,timlevett/uw-ui-toolkit,apetro/uw-ui-toolkit,apetro/uw-ui-toolkit,apetro/uw-ui-toolkit,timlevett/uw-ui-toolkit,nblair/uw-ui-toolkit,UWMadisonUcomm/uw-ui-toolkit,smargovsky/uw-ui-toolkit