small first improvement to features page
move from seven to 7 (kelley wanted that!)
add a button for the ownCloud contributor conference!
Add conference mention to developer section on features page
Add a screenshots of Documents
Relative links
Merge pull request #106 from owncloud/oc7features

Oc7features
Merge pull request #105 from owncloud/contribute

add a button for the ownCloud contributor conference!