system.web.http.webhost

This is available in the aspnetwebstack external package, however, is not currently configured  for mono to build this assembly.  I found that I needed this when I started to look at trying to host an ASP.Net Web API based on the template application from VS.

In that environment, it starts to initialize the routes for webapi via the following:

WebApiConfig.Register(GlobalConfiguration.Configuration);

The GlobalConfiguration class lives within this system.web.http.webhost assembly.

After making the changes included in this pull request, this assembly is built, and allowed my test webapi controller to execute when i include this assembly along with the test application.  The list of sources included in the source was heavily influenced from the system.web.http.selfhost assembly, which had been included already.

Please let me know if there are any questions/comments.

Thanks!
Mike