Updated to .NET 4.0 and GeoIP2

I not only modernized the API used and refreshed the database, but also reduced the IO by parsing the database only once as suggested by https://github.com/maxmind/GeoIP2-dotnet#database-usage which will be pretty huge now that we are popular and added some try/catch for unforeseeable problems like https://github.com/OpenRA/OpenRA/issues/4601

Tip: Run with `Debug.IgnoreVersionMismatch=true` to see all games in the server browser.