Modding improvements

The 'AI Considers advancing before firing' change seemed interesting, and trying to design a skills architecture was doing my head in.

I've removed the try...except thing from the Dispatcher, because my AI code was throwing type errors, and the try...except was doing my head in.
My code isn't throwing exceptions anymore - but it WAS throwing exceptions, and I couldn't get a proper stack trace because of the exception handler on the dispatcher.  And it seems to me that it would be desirable to have the exception handling working properly, and to prevent the exceptions in dispatcher from being raised, instead of working around them.

None should be easy to check for before doing the dispatcher-dictionary thing, I assume bool shouldn't be too hard to locate either.