util: the __setitem__ method on historyarraylist was meaningless, surprising nobody...

util: the __setitem__ method on historyarraylist was meaningless, surprising nobody noticed that.
types:  added PickleType, its slightly trickier than trivial, so OK now its standard.
attributes: the level of pain if an AttributeError occurs inside a CallableProp, in combination with an object that implements __getattr__,  is too deep for me to put the users through....so convert AttributeErrors to Assertions...
engine: im not a fan of catching universal exceptions and squashing them