ClientGUI: user import wildcards, add ProgressMonitor, simplified logging, add new...

ClientGUI: user import wildcards, add ProgressMonitor, simplified logging, add new functionality...

 * use import x.y.z.* wildcards to reduce clutter in header
 * use project-standardised simplified logp()
 * refactor some method names to be more descriptive e.g. loginDialog() -> doLogin()
 * add exitCleanly() to shutdown background threads
 * add setServiceTitles() to update network service Sender fields after user login
 * add ServiceAddressMap updates from Neigbour multicast announcements (no longer done by NetworkServer*)
 * Login intent: add self to members online
 * add Logout intent handling
 * replace main() with generic app handling used in all other project executables