add "(my Youtube/Vimeo video was blocked)"

thnx to https://twitter.com/EINS78/status/417790449227542531
Merge branch 'feature-german' into gh-pages
move /en/30c3/ to /30c3/ and /de/30c3/ to /30c3/de/
Merge pull request #19 from PPOE/gh-pages

Refactored 30c3 microsite