v0.1.0, 2010-12-01 -- Initial release.
v0.2.0, 2011-01-04 -- Add exc.reraise.
v0.3.0, 2011-04-13 -- Add replacefile.
v0.3.1, 2011-04-14 -- Make replacefile copy mode bits.
v0.4.0, 2012-04-26 -- Add exc.retry, retry_func.
v0.5.0, 2016-12-04 -- Add dicts, graph, toposort.
v0.6.0, 2017-10-30 -- Add tk, out, timing, ProgressBar.
v0.6.1, 2017-11-06 -- Add tk.form.Message, KeyValueField, validation hooks.
v0.6.2, 2017-11-21 -- Ensure that tk subpackage gets into tarball.
v0.6.3, 2017-11-22 -- Use find_packages() to include tk subpackage.
