Migrate to .NET 4.5 and ASP.NET MVC 5

* Upgrade solution to .NET 4.5;
* Update NuGet;
* Update dependencies:
  * CommonServiceLocator to 1.3;
  * Newtonsoft.Json to 6.0.7;
  * MHibernate 4.0.2;
  * Iesi.Collections to 4.0.1;
  * FluentNHibernate to 2.0.1;
  * ASP.NET MVC to 5.2.2;
  * RavenDB.Client to 3.0;
  * Castle to 3.3;
  * NUnit to 2.6.4
Fix compiler warnings