Issue #114 : Use sys.getfilesystemencoding for decoding config in bdist_wininst distributions.

Issue #105 and Issue #113: Establish a more robust technique for determining the terminal encoding:

1. Try ``getpreferredencoding`` 2. If that returns US_ASCII or None, try the encoding from ``getdefaultlocale``. If that encoding was a "fallback" because Python could not figure it out from the environment or OS, encoding remains unresolved. 3. If the encoding is resolved, then make sure Python actually implements the encoding. 4. On the event of an error or unknown codec, revert to fallbacks (UTF-8 on Darwin, ASCII on everything else). 5. On the encoding is 'mac-roman' on Darwin, use UTF-8 as 'mac-roman' was a bug on older Python releases. On a side note, it would seem that the encoding only matters for when SVN does not yet support ``--xml`` and when getting repository and svn version numbers. The ``--xml`` technique should yield UTF-8 according to some messages on the SVN mailing lists. So if the version numbers are always 7-bit ASCII clean, it may be best to only support the file parsing methods for legacy SVN releases and support for SVN without the subprocess command would simple go away as support for the older SVNs does.