Make some of the samples compile in Unicode mode.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18210 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/artprov/artbrows.cpp

@@ -33,7 +33,7 @@
 #include "artbrows.h"
 
 #define ART_CLIENT(id) \
-    choice->Append(#id, (void*)id);
+    choice->Append(_T(#id), (void*)id);
 #define ART_ICON(id) \
     { \
         int ind; \
@@ -42,7 +42,7 @@
             ind = images->Add(icon); \
         else \
             ind = 0; \
-        list->InsertItem(index, #id, ind); \
+        list->InsertItem(index, _T(#id), ind); \
         list->SetItemData(index, (long)id); \
         index++; \
     }