updated stb_image
updated stb_image

Conflicts:
	apps/common/miniSG/miniSG.cpp

wilsonCernWq/ospray,MengjiaoH/ospray,ospray/OSPRay,MengjiaoH/ospray,MengjiaoH/ospray,ospray/OSPRay,ospray/OSPRay,MengjiaoH/ospray,ospray/OSPRay,wilsonCernWq/ospray,wilsonCernWq/ospray,MengjiaoH/ospray