Add wxVersionInfo and functions returning it for 3rd party libraries.

Add simple wxVersionInfo class holding the version information.

Also add GetLibraryVersionInfo() static method to wx{JPEG,PNG,TIFF}Handler,
wxStyledTextCtrl and wxXmlDocument classes and wxGetZlibVersionInfo() and
wxGetLibraryVersionInfo() global functions using it.

Closes #12690.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66259 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/imagpng.h

@@ -19,6 +19,7 @@
 #if wxUSE_LIBPNG
 
 #include "wx/image.h"
+#include "wx/versioninfo.h"
 
 #define wxIMAGE_OPTION_PNG_FORMAT    wxT("PngFormat")
 #define wxIMAGE_OPTION_PNG_BITDEPTH  wxT("PngBitDepth")
@@ -46,6 +47,8 @@ public:
         m_mime = wxT("image/png");
     }
 
+    static wxVersionInfo GetLibraryVersionInfo();
+
 #if wxUSE_STREAMS
     virtual bool LoadFile( wxImage *image, wxInputStream& stream, bool verbose=true, int index=-1 );
     virtual bool SaveFile( wxImage *image, wxOutputStream& stream, bool verbose=true );