Initial implementation of new homepage header
Fix some links on the new homepage:
EE link back on home, rename install to download
Merge branch 'new-header' of github.com:owncloud/www into new-header
fix links
little wording change for contribute part
Increase homepage title font size
Fix typo
Fix indentation in homepage
Merge pull request #334 from owncloud/new-header

New homepage header