Problem: Regexp fails to match when using "\>\)\?". (Ramel)
Solution: When a state is already in the list, but addstate_here() is used
and the existing state comes later, add the new state anyway.
Problem: The example that explains nested backreferences does not work
properly with the new regexp engine. (Harm te Hennepe)
Solution: Also save the end position when adding a state. (closes#990)
