Add triple commands

[tonylukasavage]

Add a way to send commands to triple, rather than to a connected client app. The node.js repl does this with the . prefix. For example, the following tells the node.js repl to break execution:

> .break

This interface will allow for commands like break, record, replay, adding assets, etc... For now, this issue will only encompass creating this interface and the exit command.