Added TkWorker#closeSession()
Worker: removed _currentUserData global object, moved to tkWorker.currentUser
removed loading of removed test file
updated SPA tests to use new TkWorker#currentUser
renamed TkWorker#currentUser & TkWorker#currentUsers to user & users
renamed UserData#userName to UserData#name
Merge pull request #269 from n1k0/worker-globals-removal

Worker globals removal: _currentUserData