Ignore non-ascii characters in py3k filename and stdout/stderr output

Hi,

I tried to retrieve this video using youtube-dl-2013.09.07 with python 3.3:
https://www.youtube.com/watch?v=v9cJWCYdvUk

Here is the traceback:
$ youtube-dl https://www.youtube.com/watch?v=v9cJWCYdvUk
[youtube] Setting language
[youtube] v9cJWCYdvUk: Downloading video webpage
[youtube] v9cJWCYdvUk: Downloading video info webpage
[youtube] v9cJWCYdvUk: Extracting video information
Traceback (most recent call last):
  File "/usr/bin/youtube-dl", line 6, in <module>
    youtube_dl.main()
  File "/usr/lib/python3.3/site-packages/youtube_dl/__init__.py", line 667, in main
    _real_main(argv)
  File "/usr/lib/python3.3/site-packages/youtube_dl/__init__.py", line 651, in _real_main
    retcode = ydl.download(all_urls)
  File "/usr/lib/python3.3/site-packages/youtube_dl/YoutubeDL.py", line 573, in download
    videos = self.extract_info(url)
  File "/usr/lib/python3.3/site-packages/youtube_dl/YoutubeDL.py", line 339, in extract_info
    return self.process_ie_result(ie_result, download=download)
  File "/usr/lib/python3.3/site-packages/youtube_dl/YoutubeDL.py", line 422, in process_ie_result
    for r in ie_result['entries']
  File "/usr/lib/python3.3/site-packages/youtube_dl/YoutubeDL.py", line 422, in <listcomp>
    for r in ie_result['entries']
  File "/usr/lib/python3.3/site-packages/youtube_dl/YoutubeDL.py", line 369, in process_ie_result
    self.process_info(ie_result)
  File "/usr/lib/python3.3/site-packages/youtube_dl/YoutubeDL.py", line 548, in process_info
    success = self.fd._do_download(filename, info_dict)
  File "/usr/lib/python3.3/site-packages/youtube_dl/FileDownloader.py", line 376, in _do_download
    if self.params.get('continuedl', False) and os.path.isfile(encodeFilename(filename)) and not self.params.get('nopart', False):
  File "/usr/lib/python3.3/genericpath.py", line 29, in isfile
    st = os.stat(path)
UnicodeEncodeError: 'ascii' codec can't encode character '\xe3' in position 24: ordinal not in range(128)

The attached patch ignores some utf-8 but non ascii caracters originating from the title parsed html, because python3 wants ascii filenames by default. The stderr/stdout default encoding seems also to be ascii, at least for python3.

Regards,

x.