This implementation can connect to a local server and browser its
contents, but cannot download and open the documents yet.

TODO:

* Download and open documents.
* UI to configure server, user and password.
* Implement filtering to show only the documents of the desired type.
* Improve error handling.

Change-Id: I54a2e2e1d3e8ec8d824d75639e176ca452551f3e
Reviewed-on: https://gerrit.libreoffice.org/16191Reviewed-by: Jacobo Aragunde Pérez <jaragunde@igalia.com>
Tested-by: Jacobo Aragunde Pérez <jaragunde@igalia.com>
(cherry picked from commit 69773f54)