Removed inclusion of wine/winestring.h from winbase.h and added it to
the C files that need it.

diff --git a/controls/menu.c b/controls/menu.c
index ea2bc55..c536043 100644
--- a/controls/menu.c
+++ b/controls/menu.c
@@ -21,6 +21,7 @@
 #include "wingdi.h"
 #include "wine/winbase16.h"
 #include "wine/winuser16.h"
+#include "wine/winestring.h"
 #include "win.h"
 #include "task.h"
 #include "heap.h"