Add docs for getting started with fubu new
fubu new example shows Spark over Razor

Using Spark in the getting started example since it's much more common
than Razor
added round trip url definition to OwinCurrentHttpRequest
renamed ICurrentHttpRequest to IHttpRequest.  Closes GH-686
eliminated StandInHttpRequest.  Closes GH-687
all tests now use OwinHttpRequest
The beginning of InMemoryHost!
implemented proof of concept for Http scenario testing