Remove Windows CE support

Windows CE doesn't seem to be supported by Microsoft any longer. Last CE
release was in early 2013 and the PocketPC and Smartphone targets supported by
wxWidgets are long gone.

The build files where already removed in an earlier cleanup this commit
removes all files, every #ifdef and all documentation regarding the Windows CE
support.

Closes https://github.com/wxWidgets/wxWidgets/pull/81

samples/dialogs/dialogs.cpp

@@ -1675,10 +1675,6 @@ void MyFrame::FileOpenGeneric(wxCommandEvent& WXUNUSED(event) )
 
 void MyFrame::FilesOpenGeneric(wxCommandEvent& WXUNUSED(event) )
 {
-    // On PocketPC you can disable OK-only dialogs policy using system option
-    int buttons = wxSystemOptions::GetOptionInt(wxT("wince.dialog.real-ok-cancel"));
-    wxSystemOptions::SetOption(wxT("wince.dialog.real-ok-cancel"), 1);
-
     wxString wildcards = wxT("All files (*.*)|*.*|C++ files (*.cpp;*.h)|*.cpp;*.h");
     wxGenericFileDialog dialog(this, wxT("Testing open multiple file dialog"),
                         wxEmptyString, wxEmptyString, wildcards,
@@ -1706,9 +1702,6 @@ void MyFrame::FilesOpenGeneric(wxCommandEvent& WXUNUSED(event) )
         wxMessageDialog dialog2(this, msg, wxT("Selected files"));
         dialog2.ShowModal();
     }
-
-    // restore system option
-    wxSystemOptions::SetOption(wxT("wince.dialog.real-ok-cancel"), buttons);
 }
 
 void MyFrame::FileSaveGeneric(wxCommandEvent& WXUNUSED(event) )
@@ -2695,9 +2688,7 @@ void MyCanvas::OnPaint(wxPaintEvent& WXUNUSED(event) )
     dc.SetBackgroundMode(wxTRANSPARENT);
     dc.DrawText(
                 wxT("wxWidgets common dialogs")
-#if !defined(__SMARTPHONE__)
                 wxT(" test application")
-#endif
                 , 10, 10);
 }