Bump SPI minimal SSE level to 4.1 on spinux, 4.2 on OSX
Bump SPI minimal SSE level to 4.1 on spinux, 4.2 on OSX

YangYangTL/oiio,lgritz/oiio,cwilling/oiio,OpenImageIO/oiio,OpenImageIO/oiio,mcanthony/oiio,bdeluca/oiio,mcanthony/oiio,lgritz/oiio,scott-wilson/oiio,sambler/oiio,mcanthony/oiio,sambler/oiio,OpenImageIO/oiio,bdeluca/oiio,micler/oiio,scott-wilson/oiio,scott-wilson/oiio,sambler/oiio,cwilling/oiio,micler/oiio,bdeluca/oiio,OpenImageIO/oiio,lgritz/oiio,lgritz/oiio,YangYangTL/oiio,cwilling/oiio,bdeluca/oiio,YangYangTL/oiio,micler/oiio,micler/oiio,scott-wilson/oiio,cwilling/oiio,mcanthony/oiio,YangYangTL/oiio,sambler/oiio