Added background to PreferencePanel
Added background to PreferencePanel

RomzesRover/HoloEverywhere,RomzesRover/HoloEverywhere,mercadolibre/HoloEverywhere,andresesfm/HoloEverywhere-1,GrioSF/HoloEverywhere,GrioSF/HoloEverywhere,tsdl2013/HoloEverywhere,Prototik/HoloEverywhere,GrioSF/HoloEverywhere,Prototik/HoloEverywhere,imoblife/HoloEverywhere,natuan241/HoloEverywhere,imoblife/HoloEverywhere,riverfor/HoloEverywhere,riverfor/HoloEverywhere,mercadolibre/HoloEverywhere,hgl888/HoloEverywhere,natuan241/HoloEverywhere,hgl888/HoloEverywhere,andresesfm/HoloEverywhere-1,tsdl2013/HoloEverywhere