Review: fix the gcc visibility on linux


Malcolm Humphreys <malcolmh...@...>
 

- removed some #pragma's which were breaking the build on linux,
there are a few more warnings now to do with template<> visibility
in yaml-cpp but it should now link on linux (was working on OSX)
http://github.com/malcolmhumphreys/OpenColorIO/commit/378d9fb3729255bd665f216ef68a487657bd666d

.malcolm