gateone.py:  Fixed a bug where you'd get a KeyError exception if the 'enable_unix_socket' setting was missing.  It is no longer mandatory.
sso.py:  Improved error handling/logging when there's a Kerberos-specific problem.
Bookmarks plugin:  Fixed a bug where 't' was undefined.
setup.py (and others):  Moved terminal.py into its own separate module.  Apps and plugins had to have their imports corrected to reflect this.