Added SingletonInstance.h
Added SingletonInstance.h

Misterblue/LookingGlass-Viewer,Misterblue/LookingGlass-Viewer,Misterblue/LookingGlass-Viewer,Misterblue/LookingGlass-Viewer,Misterblue/LookingGlass-Viewer,Misterblue/LookingGlass-Viewer,Misterblue/LookingGlass-Viewer