This samples used "wx_append" in its bakefile, but should be using
"wx_append_base", as it's a console application.
This fixes its build with makefile.unx, as wxUSE_GUI wasn't properly
defined as 0 before.
This sample shows usage of wxArchiveStream and wxArchiveFactory.
It also allows for easy testing of wxArchiveStream implementations
outside of the unit tests.
See https://github.com/wxWidgets/wxWidgets/pull/730