first addition of media partners
made it look ok-ish
Some style changes to conf page
took ideas from providers page (tnx, Marieke!)
Fix alignment of partner banners
Fix footer social icons
Open partners in new tabs
Merge pull request #166 from owncloud/conference

I'm all good with it now. Let's get it live!
Merge pull request #177 from owncloud/master

Improve conference page