poll() function is now a static method in python, this is more correct, matching C where the operator is not created to run poll.
def poll(self, context): ...
is now...
@staticmethod
def poll(context): ...
Pythons way of doing static methods is a bit odd but cant be helped :|
This does make subclassing poll functions with COMPAT_ENGINES break, so had to modify quite a few scripts for this.
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