Store total counts on FetchingArray when fb returns a "count" attribute

Previously we were accessing the FetchingArray.count method, which was
returning the number of entries currently in the array, rather than the
total number of available entries. When displaying statistics, this
makes our numbers look small and sad.

When building a fetching array we now store a "count" attribute if
present in the total_count attribute.

lib/mogli/client.rb

@@ -177,6 +177,7 @@ def extract_fetching_array(hash,klass)
       f.concat(hash["data"])
       f.client = self
       f.classes = Array(klass)
+      f.total_count = hash["count"]
       if paging=hash["paging"]
         f.next_url = URI.encode paging["next"] unless paging["next"].nil?
         f.previous_url = URI.encode paging["previous"] unless paging["previous"].nil?

lib/mogli/fetching_array.rb

@@ -1,6 +1,6 @@
 module Mogli
   class FetchingArray < Array
-    attr_accessor :next_url, :previous_url, :client, :classes
+    attr_accessor :next_url, :previous_url, :client, :classes, :total_count
 
     def fetch_next
       return [] if next_url.nil? || next_url.empty?