Fix Haiku build.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23853 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/sudoku/SudokuView.cpp

@@ -16,9 +16,11 @@
 
 #include <Application.h>
 #include <Beep.h>
+#include <DataIO.h>
 #include <File.h>
 #include <NodeInfo.h>
 #include <Path.h>
+#include <String.h>
 
 
 const uint32 kMsgCheckSolved = 'chks';

src/apps/sudoku/SudokuView.h

@@ -9,6 +9,7 @@
 #include <View.h>
 #include <ObjectList.h>
 
+class BDataIO;
 class SudokuField;
 struct entry_ref;