Escape dev commands for chatting.

Allow chatting command strings if prefixed with "//" instead of executing (with a prefix of "/").

> Newbie01: Hey Phrohdoh, how did you give yourself cash?
> Phrohdoh: /givecash

We could either do this or players can prefix their message with a space (as is possible already).
This is actually not needed. OnChat waits for any of the traits to return false. If any of the traits return false, it does not send the chat message. However, if all the traits return true; it will send the chat message. If you just change this to `return true;` it will give the behaviour you are looking for.