Infoqscraper

- Add support of several output type
* legacy:
From the 0.0.* branch, works with ffmpeg > 0.5
* h264:
Same as legacy but use x264. Faster encoding and smaller file size.
Require a recent ffmpeg
* h264_overlay:
Display both the slides and the speake. Use x264, encoding is much
slower than h264 (~10x)
- Removed PIL dependency
- Fix some encoding issues
- Fix broken slide download due to a markup change

- Fix a regression introduced by 0.0.7, ffmpeg 0.8 does not support -n
- Remove "... presentation -c" since redundant witch "infoqscraper -c ..."

- Fix "presentation download URL"
- Add --overwrite/-y option to overwrite an already existing output file.

- Fix several regressions due to markup changes

- Create requirements-extra-python2.6.txt for python 2.6 only dependencies
- Remove html5lib dependency. The built-in parse now works fine and a bug in
BeautifulSoup 4.2.0/html5lib prevent from parsing the pages correctly

- Python 2.6 compatibility
- Fix btrfs support (handle EMLINK properly)
- ffmpeg 0.8 compatibility (and later)
- Update page scraping to reflect the new page layout (previous versions no
longer work with the new website)