Make sure loose_count returns an Integer in pg_loose_count

This is stored as a float in the PostgreSQL system catalogs,
but users probably expect a count to return an integer.

lib/sequel/extensions/pg_loose_count.rb

@@ -22,7 +22,7 @@ module LooseCount
       # Look at the table statistics for the given table to get
       # an approximate count of the number of rows.
       def loose_count(table)
-        from(:pg_class).where(:oid=>regclass_oid(table)).get(:reltuples)
+        from(:pg_class).where(:oid=>regclass_oid(table)).get(Sequel.cast(:reltuples, Integer))
       end
     end
   end

spec/adapters/postgres_spec.rb

@@ -64,6 +64,7 @@ def logger.method_missing(m, msg)
   specify "should support pg_loose_count extension" do
     @db.extension :pg_loose_count
     @db.create_table(:tmp_dolls){text :name}
+    @db.loose_count(:tmp_dolls).should be_a_kind_of(Integer)
     @db.loose_count(:tmp_dolls).should == 0
     @db.loose_count(:public__tmp_dolls).should == 0
     @db[:tmp_dolls].insert('a')

spec/extensions/pg_loose_count_spec.rb

@@ -7,11 +7,11 @@
 
   specify "should add loose_count method getting fast count for entire table using table statistics" do
     @db.loose_count(:a).should == 1
-    @db.sqls.should == ["SELECT reltuples FROM pg_class WHERE (oid = CAST(CAST('a' AS regclass) AS oid)) LIMIT 1"]
+    @db.sqls.should == ["SELECT CAST(reltuples AS integer) AS v FROM pg_class WHERE (oid = CAST(CAST('a' AS regclass) AS oid)) LIMIT 1"]
   end
 
   specify "should support schema qualified tables" do
     @db.loose_count(:a__b).should == 1
-    @db.sqls.should == ["SELECT reltuples FROM pg_class WHERE (oid = CAST(CAST('a.b' AS regclass) AS oid)) LIMIT 1"]
+    @db.sqls.should == ["SELECT CAST(reltuples AS integer) AS v FROM pg_class WHERE (oid = CAST(CAST('a.b' AS regclass) AS oid)) LIMIT 1"]
   end
 end