Implement feeds

Implement point of interests and associated feeds.

There are two feeds for every POI, audio and visual. While being close to a POI
the feeds get appended to the global feeds.
Merge branch 'master' of https://github.com/MDI-F2/MDI-F2.github.io into source

Conflicts:
	_includes/index.markdown
	_site/css/prototype.css
	_site/index.html
	_site/javascripts/prototype.js
Revert "Implement feeds"

This reverts commit 27581aaf9e9cd32b0d60de8c8eabe00eec969f54.
Revert "Revert "Implement feeds""

This reverts commit e983bb152c4e756f8bac2081c531dd3bbc9b5fc2.
Fix problems with merge