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/zstream.h

@@ -16,6 +16,7 @@
 #if wxUSE_ZLIB && wxUSE_STREAMS
 
 #include "wx/stream.h"
+#include "wx/versioninfo.h"
 
 // Compression level
 enum wxZlibCompressionLevels {
@@ -138,6 +139,8 @@ private:
     DECLARE_DYNAMIC_CLASS(wxGzipClassFactory)
 };
 
+WXDLLIMPEXP_BASE wxVersionInfo wxGetZlibVersionInfo();
+
 #endif
   // wxUSE_ZLIB && wxUSE_STREAMS