This patch introduces a new server config server.stream-narrow-clones which if
set to True will advertise that the server supports narrow stream clones.
This patch also pass on the includes and excludes from getbundle command to
streamclone generation code.
There is a test added to show that the includepats and excludepats are correctly
passed.
Upcoming patches will implement storage layer filtering for streamclones and
then we can remove the temporary error and plug in the whole logic together to
make narrow stream clones working.
I had to change these to kwargs.get() to get test-http.t and many others to pass. (I also fixed the typo in the comment above)