New release of the Windows installer from Thomas Heller.

New release of the Windows installer from Thomas Heller.
The known bug (bogus error message when an empty file is
extracted) is fixed.

Other changes:

- The target-compile and target-optimize flags of bdist_wininst
  are gone. It is no longer possible to compile the python
  files during installation.
- The zlib module is no longer required or used by bdist_wininst.

- I moved the decompression/extraction code into a separate
  file (extract.c).

- The installer stub is now compressed by UPX (see
  http://upx.tsx.org/). This reduces the size of the exe
  (and thus the overhead of the final installer program)
  from 40 kB to 16 kB.

- The installer displays a more uptodate user wizard-like
  user interface, also containing a graphic: Just's Python Powered logo.
  (I could not convince myself to use one of the BeOpen logos).
- The installation progress bar now moves correctly.