The error message when there's no Startup class specified sucks

[davidfowl]

System.ArgumentException: Value cannot be null or empty.
Parameter name: startupAssemblyName
   at Microsoft.AspNet.Hosting.Startup.StartupLoader.FindStartupType(String startupAssemblyName, IList`1 diagnosticMessages)
   at Microsoft.AspNet.Hosting.Internal.WebApplication.EnsureStartup()
   at Microsoft.AspNet.Hosting.Internal.WebApplication.EnsureApplicationServices()
   at Microsoft.AspNet.Hosting.Internal.WebApplication.BuildApplication()
   at Microsoft.AspNet.Hosting.WebApplicationBuilder.Build()
   at ConsoleApp1.Program.Main(String[] args) in c:\dev\scratch\WebApplication10\src\ConsoleApp1\Program.cs:line 13
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.Dnx.Runtime.Common.EntryPointExecutor.Execute(Assembly assembly, String[] args, IServiceProvider serviceProvider)
   at Microsoft.Dnx.ApplicationHost.Program.<>c__DisplayClass3_0.<ExecuteMain>b__0()
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()

/cc @Tratcher @JunTaoLuo