Weekly update

Not much was going on during this week, as I was away for couple of days and had some other things to do, but here's the list (before I go to bed):
-added limit for number of simultaneously executed code blocks (limit per code block)
-added weighted queries. well, just one at the moment - distance - but the code's there and adding new ones can't be any easier
-added two operators: missing "not equal" operator (I have no idea how I missed that) and "tagged" - although tagging is not there.