a few code improvements an testing for preferencemanager

Network Share Mounter/helper/ActivityController.swift

Network Share Mounter/helper/AutomaticSignIn.swift

Network Share Mounter/helper/Logger.swift

Network Share Mounter/helper/NSTaskWrapper.swift

Network Share Mounter/lookups/SRVRecord.swift

Network Share Mounter/lookups/SRVResolver.swift

Network Share Mounter/preferences/FAU.swift

Network Share Mounter/preferences/PreferenceKeys.swift

Network Share Mounter/preferences/PreferenceManager.swift

... MounterTests/ManagerTests/KeychainManagerMockTests.swift

...hare MounterTests/ManagerTests/KeychainManagerTests.swift

...re MounterTests/ManagerTests/PreferenceManagerTests.swift

networkShareMounter.xcodeproj/project.pbxproj