rename DllExport to IIR_EXPORT, since the former is a too generic name
always define IIR_EXPORT to empty in static lib (there was a __declspec(dllexport) during build of static lib on Windows, not good).
hide all private symbols regardless of os/compiler
do not try to export templates, they can't be exported by definition (except explicit instantiations, but it's tricky and there is no explicit instantiation in iir1)
DllExporttoIIR_EXPORT, since the former is a too generic nameIIR_EXPORTto empty in static lib (there was a__declspec(dllexport)during build of static lib on Windows, not good).