* GetByHeight will now switch to using binary search once
we have >=50 items.
* Feedback from @ebuchman to catch a missed spot where
we forgot about lazy sorting that the original code
assumed would always have sorted commits by height.
Added a lazy sorting routine here too.
A test as well to ensure that we always get the properly
sorted and last value.
Addressing PR review requests from @melekes and @ebuchman to
add a test that checks that the heights returned from both are
the same thus providing a perceptible equivalence of the code
linear range search vs binary range search code.
Jae Kwon
Emmanuel Odeke
Ethan Frey
Anton Kaliaev
Adrian Brink