Add a simple GUI for Windows users

[ssokolow]

Since this was partly intended as an alternative to ED64-Saveswap which doesn't set off virus scanners too eager to see EXE-ified AutoIt scripts as viruses, I should offer up a py2exe-bundled version of this with a simple GUI.

One of the questions I'll need to answer is what GUI API to use. I'm currently leaning toward wxPython for the following reasons:

1. It wraps MFC on Windows so it should feel more native than PyGTK
2. It wraps MFC on Windows, so it should result in a significantly smaller EXE than something which needs to carry along GTK+ or Qt libraries.
3. It still works on Linux and doesn't have Tkinter's "ugly on Linux" problem.

...ideally, with the compression tricks I've learned, I should be able to produce something smaller than the 1MiB size of ED64-Saveswap without triggering any false positives on VirusTotal. (After all, I got something which had to carry along libxml, Unicode tables, and SSL support down to 3MiB and this uses none of those.)