Updated data stream version for Qt 4.9 and 5.0

For now, using the same version as 4.8. This needs to be corrected
when the actual data stream version is known.

src/corelib/io/qdatastream.h

@@ -86,10 +86,11 @@ public:
         Qt_4_5 = 11,
         Qt_4_6 = 12,
         Qt_4_7 = Qt_4_6,
-        Qt_4_8 = Qt_4_7
-#if QT_VERSION >= 0x040900
+        Qt_4_8 = Qt_4_7,
+        Qt_4_9 = Qt_4_8,
+        Qt_5_0 = Qt_4_8
+#if QT_VERSION >= 0x050100
 #error Add the datastream version for this Qt version
-        Qt_4_9 = Qt_4_8
 #endif
     };