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

src/common/dlgcmn.cpp

@@ -223,47 +223,15 @@ wxSizer *wxDialogBase::CreateTextSizer(const wxString& message,
 
 wxSizer *wxDialogBase::CreateButtonSizer(long flags)
 {
-#ifdef __SMARTPHONE__
-    wxDialog* dialog = (wxDialog*) this;
-    if ( flags & wxOK )
-        dialog->SetLeftMenu(wxID_OK);
-
-    if ( flags & wxCANCEL )
-        dialog->SetRightMenu(wxID_CANCEL);
-
-    if ( flags & wxYES )
-        dialog->SetLeftMenu(wxID_YES);
-
-    if ( flags & wxNO )
-        dialog->SetRightMenu(wxID_NO);
-
-    return NULL;
-#else // !__SMARTPHONE__
-
 #if wxUSE_BUTTON
 
-#ifdef __POCKETPC__
-    // PocketPC guidelines recommend for Ok/Cancel dialogs to use OK button
-    // located inside caption bar and implement Cancel functionality through
-    // Undo outside dialog. As native behaviour this will be default here but
-    // can be replaced with real wxButtons by setting the option below to 1
-    if ( (flags & ~(wxCANCEL|wxNO_DEFAULT)) != wxOK ||
-            wxSystemOptions::GetOptionInt(wxT("wince.dialog.real-ok-cancel")) )
-#endif // __POCKETPC__
-    {
-        return CreateStdDialogButtonSizer(flags);
-    }
-#ifdef __POCKETPC__
-    return NULL;
-#endif // __POCKETPC__
+    return CreateStdDialogButtonSizer(flags);
 
 #else // !wxUSE_BUTTON
     wxUnusedVar(flags);
 
     return NULL;
 #endif // wxUSE_BUTTON/!wxUSE_BUTTON
-
-#endif // __SMARTPHONE__/!__SMARTPHONE__
 }
 
 wxSizer *wxDialogBase::CreateSeparatedSizer(wxSizer *sizer)