Hyperlinks to Quaddicted map page and full-size screenshot

Make clicking the map thumbnail open the full screenshot (in a browser), and clicking the map title above the thumbnail open the quaddicted review page

the corresponding issues are:
https://github.com/hrehfeld/QuakeInjector/issues/79
https://github.com/hrehfeld/QuakeInjector/issues/74

Also, I removed the BrowserLauncher2 dependency because it wasn't working on my system (OSX 10.9) and there is an official API available since JDK6 we can use: http://docs.oracle.com/javase/6/docs/api/java/awt/Desktop.html#browse(java.net.URI)