Add some 'const &' as should always have been.
Add some 'const &' as should always have been.


git-svn-id: 93cebb81a0f5cc00f31a7ad40d16024532691b70@261 a3683778-fedd-11de-87c3-653bb6514e15

fpsunflower/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,lgritz/OpenShadingLanguage,mcanthony/OpenShadingLanguage,gzorin/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,juvenal/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,gzorin/OpenShadingLanguage,Anteru/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,brechtvl/OpenShadingLanguage,brechtvl/OpenShadingLanguage,brechtvl/OpenShadingLanguage,juvenal/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,gzorin/OpenShadingLanguage,mcanthony/OpenShadingLanguage,rlmh/OpenShadingLanguage,aconty/OpenShadingLanguage,svenstaro/OpenShadingLanguage,aconty/OpenShadingLanguage,svenstaro/OpenShadingLanguage,lgritz/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,imageworks/OpenShadingLanguage,aconty/OpenShadingLanguage,rlmh/OpenShadingLanguage,gzorin/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,Anteru/OpenShadingLanguage,lgritz/OpenShadingLanguage,sjparker/OpenShadingLanguage,brechtvl/OpenShadingLanguage,mcanthony/OpenShadingLanguage,imageworks/OpenShadingLanguage,imageworks/OpenShadingLanguage,mcanthony/OpenShadingLanguage,aconty/OpenShadingLanguage,rlmh/OpenShadingLanguage,sjparker/OpenShadingLanguage,lgritz/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,svenstaro/OpenShadingLanguage,sjparker/OpenShadingLanguage,rlmh/OpenShadingLanguage,Anteru/OpenShadingLanguage,brechtvl/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,juvenal/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,imageworks/OpenShadingLanguage,juvenal/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,aconty/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,svenstaro/OpenShadingLanguage,lgritz/OpenShadingLanguage,Anteru/OpenShadingLanguage,sjparker/OpenShadingLanguage,imageworks/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,gzorin/OpenShadingLanguage