When re-drawing or re-caching all items, we need to search the full
rtree, including for those items that live outside of the limits of
BBOX2I. This forces the maximum BBOX2I to the full RTree limits
This reverts the previous work-around 7d62f14dd for the RTree splitting
degeneracy that was placed prior to v5. It appears not to have worked
for all systems. In its place, we use doubles instead of floats to
calculate the bounding box when filling the RTree. This keeps maximum
volume items from overlapping with the system boundary in test cases.
Seth Hillbrand
Maciej Suminski