JPEG: write density fields into header properly. Didn't realize that jpeg_set_defaults would clobber those fields.
JPEG: write density fields into header properly.
Didn't realize that jpeg_set_defaults would clobber those fields.

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