R-Trees (and in the future also R*-Trees)
====================
R-Tree is a spatial data structure similar to Quadtrees or B-Trees.
An R-Tree is a balanced tree and optimized for lookups. This implemetation useses an R-Tree to privide
a map to arbitrary values.
Some function names clash with "Prelude" names, therefore this module is usually
imported ```qualified```, e.g.:
> import Data.RTree (RTree)
> import qualified Data.RTree as RT
this implemetation is incomplete at the moment. Feel free to send comments, patches or merge requests.