GitLab

Bind to new TerminalService when UI is running, and keep service
started as long as terminals are active.  Use ViewPager to show
multiple active terminals, and menu items to open/close terminals.

Anti-alias terminal text.  Reduce callback logging.  Add method to
stop a running shell; still need to kill child process.

Change-Id: I8efcb43aeaf8813762cd0ceebcd5388fc51ebaab