include: Add some missing MAPI defines.

include/mapix.h

@@ -65,6 +65,9 @@ typedef ULONG                   FLAGS;
 #define MAPI_SIMPLE_DEFAULT  (MAPI_LOGON_UI|MAPI_ALLOW_OTHERS|MAPI_FORCE_DOWNLOAD)
 #define MAPI_SIMPLE_EXPLICIT (MAPI_NEW_SESSION|MAPI_EXPLICIT_PROFILE|MAPI_FORCE_DOWNLOAD)
 
+#define MAPI_MULTITHREAD_NOTIFICATIONS  0x00000001
+#define MAPI_NO_COINIT                  0x00000008
+
 typedef struct tagMAPIINIT_0
 {
     ULONG ulVersion;