Deprecated itemize actions and improved targeting for look actions.
The itemize actions only existed as a shortcut for providing room descriptions when entering a room. Removing it eliminates some undesirable side effects and simplifies the process of overriding [look parent] actions.
Tty::Engine does not use TerminalThread.
The TerminalThread class is deprecated due to race conditions and compatibility problems. The experimental code has been moved to a separate branch.