Merge pull request #13 from PocketScientists/master

Fixed crash when delegate doesn't respond to mapView:viewForAnnotation:
Merge pull request #14 from PocketScientists/master

Added delegate method to set visibility of cluster annotation's subtitle
Merge pull request #15 from PocketScientists/master

Fixes bug with the new delegate method.
Enable handling of custom MKUserLocation annotations
Merge pull request #17 from xfyre/master

Enable handling of custom MKUserLocation annotation
Merge branch 'master' of https://github.com/applidium/ADClusterMapView