effective config: specific view cases

effective config: specific view cases

User specified views don't override default views. In particular, the
_bind/CH view is still active. However, the order is important: if the
user defines a foo/CH view, it must be able to override _bind/CH by
matching clients first (this is how the view is documented).

The server configuration code is now simpler; it only has to build the
views based on the effective view list, and only creates the _default
view if there are no explicit views created by the user.