Add reference to SpecFlow
Modules are now called Features.
Remove Dolstagis.Web.Owin. We're not going to use it.
Convert string collections to Owin-style IDictionary<string, object>

This is only a temporary measure, so the NameValueCollectionAdapter isn't
rigorously implemented. It will be replaced by a proper Owin hosting mechanism
in due course.
Add skeleton for Owin AppFunc getter

This hasn't been implemented yet -- it's just a placeholder for now.
Rename Path and AppRelativePath to AbsolutePath and Path respectively.

This makes things more consistent with Owin terminology.
Add PathBase property to IRequest.

This will replace PathBase in ApplicationContext.
Remove IApplicationContext interface and everything that uses it.

The only purpose that this interface serves is to allow functionality that
depends on the physical path to the application. Since the Owin specification
doesn't expose this, we can't assume that we will have access to it, so don't
expose it here.

If needed, we can make it available for specific providers (e.g. the ASP.NET
provider) using extension methods.
Remove PhysicalPath from Application and ApplicationContext

See previous commit for rationale. Physical path won't be exposed by default,
only as extension methods for specific implementations (e.g. ASP.NET) if needed.
Remove VirtualPath from Application/ApplicationContext

Same rationale as for PhysicalPath. VirtualPath is now exposed through IRequest
as the PathBase property.
Implement Owin IRequest.

Still to do: stuff that involves parsing the form.
Create new HttpDictionary and RequestHeaders to replace RequestContext.
Request.Body. Needs corresponding IRequest property.
Remove RequestContext class.
Rename Response.ResponseStream to Response.Body
Add Response implementation and ResponseHeaders class.
Implement IResponse for Owin and ASP.NET
Remove IResponseContext and move cookie handling to ResponseHeaders
Move Owin environment dictionary keys to constants.
Keys for extensions listed in Owin Common Keys document