Simon Ser

Right now we have a workaround for trailing slashes in dir URLs: https://github.com/emersion/go-webdav/blob/9e23289610195c6e74d3b11064360dc48c31598f/carddav/client.go#L461 Would be nice to find a better long-term solution.

Right now `addressbook-multiget` request will result in many `GetAddressObject` calls. This is not great for backends which need to fetch resources from a remote server.

It may be desirable to have a base WebDAV filesystem, with some CalDAV/CardDAV endpoints. This should work fine except for [principals](https://tools.ietf.org/html/rfc3744#section-4). We need to figure out a way to share...

During e.g. a DELETE or COPY operation, the server can return a multistatus response. We need to handle it and check whether there are any failed responses in it.

Right now backends can only support a single address book.

If a server write operation failed, send a multistatus instead of an HTTP error.

Stop checking for e.g. `os.IsNotExist` in the server code. Do it in `LocalFileSystem` instead.

If the server returns query parameters in a href, it'll get stripped. Does it matter? If it does, we'll need to expose `href *url.URL` values instead of `path string`.

- [ ] Client - [ ] Server: dead properties should be obtained from the backend. PROPPATCH requests should be forwarded to the backend.