Improve interval tree traversal time by 4%
Improve interval tree traversal time by 4%

Before checking all the intervals stored in 'this' node, test whether it
actually contains an interval whose maximum value is at least 'y' if 'y'
is smaller than 'center'; or whose minimum value is at most 'y' if 'y'
is greater than 'center'.
The minimum/maximum values are cached during tree construction.
JOML-CI/JOML,JOML-CI/JOML,JOML-CI/JOML