Missing support for bulk PROPFIND requests

[paulmillar]

The get_property method already exists, which allows querying of properties via the WebDAV PROPFIND method. This is limit to querying a single WebDAV property.

The underlying WebDAV PROPFIND method supports querying multiple properties in one HTTP request. Under certain circumstances, querying multiple properties in a single request could bring significant performance benefits. Examples include when there is high network latency or when the WebDAV server spends significant time preprocessing each request.

Therefore, I think it would be a useful addition if the client were updated to support an additional method to allow querying multiple properties with a single PROPFIND request.

(Interestingly, this feature already exists for the set_property method via the set_property_batch method. Although the implementation seems to be incomplete as this method appears to be missing from the Resource API.)