Update Raven.Docs.shfbproj to use .NET 4.5
Re-enable generating the docs
Fix some breaking changes. Need to remove Cached Framework Comments Index Data, Cached Reflection Index Data, Cached MSDN URL References as per http://www.ewoodruff.us/shfbdocs/html/fef9e0ed-864b-42f9-8747-af4d156a7c0e.htm