pyRete update

It's been awhile since I've mentioned what's happening with pyRete. I'm still in the middle of refactoring the Rete implementation and, more importantly, the rule compiler (which is a bloated mess at the moment). I wanted to make most of these changes in one fell swoop, but I soon realized that I'm not even half the programmer required to pull that off. So instead I'm slowly (but steadily) modifying Rete node implementations and the rule compiler. Among other things, the single Not node works as expected now but there's still lots of things to do...