ASP.NET vNext support

[yannisgu]

I have seen in your roadmap, that ASP.NET vNext is planned for v0.6, but I thought it would be nice to have an GitHub issue to share some thoughts about it 😄

As far as I understood the whole thing, there are two possibilities to implement an ASP.NET vNext Web-Server. Either the "traditional" way, the Server provides an executable and then calls the Web Application, like IIS does and like HyperFastCgi is currently implemented. But I have not seen any (open) implementation for ASP.NET vNext so far.
The other way is to provide a DLL, which is called by "Microsoft.AspNet.Hosting" and configured in the project.json.

An example of the 2nd implementation is firefly.
For HyperFastCgi I see the following additions:

• An implementation of IServerFactory
  • The start would not simmilar code than Main
• A new application host
  • Needs an CallContext which implements IHttpRequestFeature and IHttpResponseFeature
  • In ProcessRequest, the delegate passed to IServerFactory must be called, with the CallContext containing the request informations
    ** The call must be awaited and then the values from the response-values from CallContext must be set to the IWebResponse

[xplicit]

The second way is the way I thought to implement ASP.NET vNext support. And exactly the firefly library is the base I would start from. I think about the additional HyperFastCgi.vNext.dll which will reference vNext interface and HyperFastCgi code and provides all necessary classes for ASP.NET vNext server.