Added a link to google api info on accuracy

lib/geokit/mappable.rb

@@ -314,9 +314,12 @@ class GeoLoc < LatLng
     # Attributes set upon return from geocoding.  Success will be true for successful
     # geocode lookups.  The provider will be set to the name of the providing geocoder.
     # Finally, precision is an indicator of the accuracy of the geocoding.
-    attr_accessor :success, :provider, :precision, :accuracy
+    attr_accessor :success, :provider, :precision
     # Street number and street name are extracted from the street address attribute.
     attr_reader :street_number, :street_name
+    # accuracy is set for Yahoo and Google geocoders, it is a numeric value of the 
+    # precision. see http://code.google.com/apis/maps/documentation/geocoding/#GeocodingAccuracy
+    attr_accessor :accuracy
 
     # Constructor expects a hash of symbols to correspond with attributes.
     def initialize(h={})