Allow use of 'nearbys' in Arel method chains.

The 'nearbys' method previously returned an array. It now returns a scope,
which is much better. It was also passing an options argument to
default_near_scope_options which was being ignored. It is no longer ignored,
but passing options this way is now deprecated due to the scope chaining
syntax provided by Rails 3. Support for Rails 2 will be discontinued soon,
or at least moved to a different branch.

lib/geocoder.rb

@@ -106,13 +106,27 @@ module Geocoder
     def default_near_scope_options(latitude, longitude, radius, options)
       lat_attr = geocoder_options[:latitude]
       lon_attr = geocoder_options[:longitude]
+      conditions = \
+        ["#{lat_attr} BETWEEN ? AND ? AND #{lon_attr} BETWEEN ? AND ?"] +
+        coordinate_bounds(latitude, longitude, radius)
+      
+      # Handle conditions. Passing of conditions by developers is deprecated
+      # but we will still need to handle conditions so, for example, we can
+      # exclude objects by ID from the nearbys method. This is incredibly
+      # ugly and doesn't work for a conditions hash: try using Arel?
+      if options[:conditions].is_a?(String)
+        options[:conditions] = [options[:conditions]]
+      end
+      if options[:conditions].is_a?(Array)
+        conditions[0] = "(#{conditions[0]}) AND #{options[:conditions][0]}"
+        conditions << options[:conditions][1]
+      end
+      
       {
         :order  => options[:order],
         :limit  => options[:limit],
         :offset => options[:offset],
-        :conditions => \
-          ["#{lat_attr} BETWEEN ? AND ? AND #{lon_attr} BETWEEN ? AND ?"] +
-          coordinate_bounds(latitude, longitude, radius)
+        :conditions => conditions
       }
     end
     
@@ -164,9 +178,17 @@ module Geocoder
   # (<tt>:order</tt>, <tt>:limit</tt>, and <tt>:offset</tt>).
   #
   def nearbys(radius = 20, options = {})
+    if options != {}
+      warn "DEPRECATION WARNING: The 'options' argument to the nearbys " +
+        "method is deprecated and will be removed from rails-geocoder in " +
+        "version 0.9.4. Nearbys now returns a scope so you should specify " +
+        "more scopes and/or conditions via chaining. For example: " +
+        "city.nearbys(20).order('name').limit(10). Support for Rails 2.x " +
+        "will be discontinued after rails-geocoder 0.9.3."
+    end
     return [] unless geocoded?
-    options = {:conditions => ["id != ?", id]}.merge(options)
-    self.class.near(read_coordinates, radius, options) - [self]
+    options.reverse_merge!(:conditions => ["id != ?", id])
+    self.class.near(read_coordinates, radius, options)
   end
   
   ##