Add login/logout to TestCase base class
Add user parameter to tag manager
Added searchByTags to view, storage and cache
Make $userId mandatory for searchByTags

$userId is now a mandatory parameter for searchByTags.

Also fixed some places in the code where the argument was missing (Node
API and View)
Added searchByTag in cache jail wrapper
Merge pull request #12778 from owncloud/searchbytags2

Added searchByTags to view, storage and cache