-added minLatitudeDeltaToCluster property, defining the new way to set a zoom level to perform clustering. the reason behind this is because Longitude distances vary too much depending on the latitude value, but latitude does not, thus making it a more suitable value to use for the task.
-deprecated the previous  minLongitudeDeltaToCluster so that in the next version it will be completely removed (for now it takes both latitude and longitude values into account, to keep version compatibility).
Merge branch 'release/1.0.5'