Bug 184681 qt port fails to compile in plugins code

X and Qt don't get along...
r=peterl sr=roc+moz a=roc+moz

modules/plugin/base/src/nsPluginHostImpl.cpp

@@ -41,6 +41,11 @@
 
 #include "nscore.h"
 #include "nsPluginHostImpl.h"
+#ifdef MOZ_WIDGET_QT
+#undef CursorShape /*X.h defines it as 0,
+                     qnamespace.h makes an enum type by that name
+                   */
+#endif
 #include <stdio.h>
 #include "prio.h"
 #include "prmem.h"