Patch [ 584078 ] Misc samples fixes from Dimitri Schoolwerth

Addresses:
  printf-format warinigs
  indentation/style
  unused variable warnings
  used wxID_ABOUT for about menu entry
  removed references to "minimal sample" in other samples
  some other misc warinigs


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@16339 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/artprov/arttest.cpp

@@ -195,7 +195,8 @@ void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
     msg.Printf( _T("This is the about dialog of wxArtProvider sample.\n")
                 _T("Welcome to %s"), wxVERSION_STRING);
 
-    wxMessageBox(msg, _T("About Minimal"), wxOK | wxICON_INFORMATION, this);
+    wxMessageBox(msg, _T("About wxArtProvider sample"),
+        wxOK | wxICON_INFORMATION, this);
 }
 
 void MyFrame::OnBrowser(wxCommandEvent& WXUNUSED(event))