message: potential fix for MSVC12
diff: @@ -234,8 +234,8 @@ namespace ospray {
  std::function<void(OSPError, const char*)>
  error_fcn { [](OSPError, const char*){} };
  - OSPError lastErrorCode {OSP_NO_ERROR};
  - std::string lastErrorMsg {"no error"};
  + OSPError lastErrorCode = OSP_NO_ERROR;
  + std::string lastErrorMsg = "no error";// no braced initializer for MSVC12
  private:
  