During setup check for multiple hosts, path, users

[AutoImport-jochen314]

Hi,

I reworked the getCurrentUserPrincipal() in DavResourceFinder to be able to check for a list of domains, path, and users.
This should fix issues like #465 and #439.

I hope this satisfies you quality requirements
If not, I am willing to improve...

[AutoImport-jochen314]

I rebased after the latest commits on head: #558