Fix MIT extractor for Python 2.6

The HTML for the MIT page does not parse cleanly for Python 2.6 due
to script tags within an actual script element.  The offending piece
is inside a comment block, so removing all such comment blocks
fixes the parsing.
Fix detection of the webpage charset if it's declared using ' instead of "

Like in "<meta charset='utf-8'/>"
Also print the field that fails if it is a md5 checksum
Update descriptions checksum for some test for Unistra and Youtube
Merge pull request #1342 from whydoubt/fix_mit_26

Fix MIT extractor for Python 2.6
Add an extractor for orf.at (closes #1346)

Make find_xpath_attr also accept numbers in the value
Fix orf.at extractor by adding file coding mark
Merge pull request #1347 from whydoubt/fix_orf_at

Fix orf.at extractor by adding file coding mark
[ign] extract videos from articles pages
[ign] update 1up extractor to work with the updated IGNIE
[youtube] update algo for length 86 (fixes #1349)
[youtube] update algo for length 84

Only appears sometimes, nearly identical to length 86.
release 2013.08.29
Merge branch 'master' into js-generator