Fixed: moved pugixml to iomei.cpp from object.cpp, reverted m_svgNodeStack to std::list

-Reverted m_svgNodeStack back to std::list

-DocObject::ReadRdgClass now only adds the string to a vector of strings instead of reading the pugi::xml_node

-MeiInput::GetRdgClass now reads the class off and passes it to the DocObject.