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

include/wx/generic/propdlg.h

@@ -21,11 +21,8 @@ class WXDLLIMPEXP_FWD_CORE wxBookCtrlBase;
 
 //-----------------------------------------------------------------------------
 // wxPropertySheetDialog
-// A platform-independent properties dialog.
-//
-//   * on PocketPC, a flat-look 'property sheet' notebook will be used, with
-//     no OK/Cancel/Help buttons
-//   * on other platforms, a normal notebook will be used, with standard buttons
+// A platform-independent properties dialog with a notebook and standard
+// buttons.
 //
 // To use this class, call Create from your derived class.
 // Then create pages and add to the book control. Finally call CreateButtons and
@@ -126,7 +123,7 @@ public:
 
 /// Operations
 
-    // Creates the buttons (none on PocketPC)
+    // Creates the buttons
     virtual void CreateButtons(int flags = wxOK|wxCANCEL);
 
     // Lay out the dialog, to be called after pages have been created
@@ -141,9 +138,6 @@ public:
     // Adds the book control to the inner sizer.
     virtual void AddBookCtrl(wxSizer* sizer);
 
-    // Set the focus
-    void OnActivate(wxActivateEvent& event);
-
     // Resize dialog if necessary
     void OnIdle(wxIdleEvent& event);