Implemented the ErrorInfo interfaces.

diff --git a/include/oleidl.h b/include/oleidl.h
index 34b4865..6abc662 100644
--- a/include/oleidl.h
+++ b/include/oleidl.h
@@ -20,6 +20,7 @@
 #include "wine/obj_cache.h"
 #include "wine/obj_oleobj.h"
 #include "wine/obj_oleview.h"
+#include "wine/obj_errorinfo.h"
 
 #endif /* __WINE_OLEIDL_H */