New version with minor API changes

It is crazy but true, in one day we have two versions.
This new version allow things like:

kb:defrule"factorial":
  pattern{ "Factorial", "?x", "?y" }:
  pattern{ "Limit", "?z" }:
  u"x < z":
  ENTAILS"=>":
  fassert{ "Factorial", u"x+1", u"y*(x+1)" }

which allow you to define very compact rules, with a simple syntax.