Updated config file and transform to remove webdav module.

Webdav can cause issues when making PUT requests via the NuGet API.
Added an InternalPath for downloading PDB files internally.

Added an InternalPath for downloading PDB files internally. The external
path did not support load balancing and caused errors when the request
was made through a load balancer.  By adding an InternalPath to the
config interface, you can differentiate between internal calls and
external calls.