Adds missing lines for previous commit.

(Updates MNO so it works for intervals that are not inserted. It searches for the splitnode and then the endpoints, updating MNO on the way back if necessary. It won't update if interval was not inserted, and only call the update function, when the value actually needs updating.)
Makes findMinNode static
Adds extension method to IInterval<T> to check if an interval has an endpoint
Adds method to Node iterate through intervals with endpoint in that node
Adds incomplete, but still unused, method for removing nodes in IBS AVL
Merge branch 'master' of https://github.com/lundmikkel/C5