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/xml/xml.h

@@ -19,6 +19,7 @@
 #include "wx/string.h"
 #include "wx/object.h"
 #include "wx/list.h"
+#include "wx/versioninfo.h"
 
 #ifdef WXMAKINGDLL_XML
     #define WXDLLIMPEXP_XML WXEXPORT
@@ -35,7 +36,6 @@ class WXDLLIMPEXP_FWD_XML wxXmlIOHandler;
 class WXDLLIMPEXP_FWD_BASE wxInputStream;
 class WXDLLIMPEXP_FWD_BASE wxOutputStream;
 
-
 // Represents XML node type.
 enum wxXmlNodeType
 {
@@ -299,6 +299,8 @@ public:
     void SetEncoding(const wxString& enc) { m_encoding = enc; }
 #endif
 
+    static wxVersionInfo GetLibraryVersionInfo();
+
 private:
     wxString   m_version;
     wxString   m_fileEncoding;