Fix from M Joonas Pihlaja: make sure atomicity.h is found for both old and new gcc versions (it moved as of gcc 4.2).
Fix from M Joonas Pihlaja: make sure atomicity.h is found for both old
and new gcc versions (it moved as of gcc 4.2).


git-svn-id: c3edda122e248ef33995da003806c930f62b9468@548 31904243-a364-42ac-a3db-9305396518ba

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