On the main page of resource site, the ribbon at top right shows open-ra.org and links to the old website. This commit changes the link to openra.net and also provides the accompanying image files.
Make some corrections
-text on ribbon is in Dejavu Sans bold
-changed link text to "Visit OpenRA official website"
Merge pull request #199 from deniz1a/fix-ribbon

Change ribbon link and image to openra.net