wininet: If we receive an error from InitializeSecurityContext in HTTP_DoAuthorization then set pAuthInfo->finished so that we don't carry on using the security context.

wininet: Assume that if we're connected to an HTTP/1.1 server then connections can be kept alive by default.

So don't close the connection in this case in HTTP_FinishedReading.

Also checks for VFW_E_NOT_STOPPED that is allowed to cause a
disconnection to fail.

RemoveFilter is better at removing a filter from a filtergraph then
some method there.

dsound: Set the status from STATE_STARTING to STATE_PLAYING before mixing our next buffer so that we do not potentially skip early event when starting.

NullRenderer might accidentally be rendered otherwise.

This just uses enumeratepins to find 2 non-connected pins and connects
them using the filtergraph.

ICaptureGraphBuilder::RenderStream needs to enumerate pins, and to
prevent duplication I implemented a bit of findpin first.