[SofaKernel] Adding SOFA_CORE_API to avoid compilation problem.
[SofaKernel] Adding SOFA_CORE_API to avoid compilation problem.

FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa