1. undid my wrong fix to wxWindowBase::Centre

2. corrected fatal bug in wxCheckLstBox (double deletion of items)
3. wxTextCtrl::SetValue() only does it if the new text is different from
   the old one
4. wxBitmap(const wxIcon&) ctor added
5. compilation fixes for VC++ and generic Win32 implementation of
   wxGetCurrentTime() in timercmn.cpp


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@4534 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/bitmap.h

@@ -140,6 +140,11 @@ public:
 
   // If depth is omitted, will create a bitmap compatible with the display
   wxBitmap(int width, int height, int depth = -1);
+
+  // we must have this, otherwise icons are silently copied into bitmaps using
+  // the copy ctor but the resulting bitmap is invalid!
+  wxBitmap(const wxIcon& icon);
+
   ~wxBitmap();
 
   virtual bool Create(int width, int height, int depth = -1);