Added OrderedHash#inspect which preserves key order

lib/mongo/util/ordered_hash.rb

@@ -51,4 +51,10 @@ class OrderedHash < Hash
     super(other)
   end
 
+  def inspect
+    str = '{'
+    str << @ordered_keys.collect { |k| "\"#{k}\"=>#{self.[](k).inspect}" }.join(", ")
+    str << '}'
+  end
+
 end

tests/test_ordered_hash.rb

@@ -79,4 +79,8 @@ class OrderedHashTest < Test::Unit::TestCase
     assert_equal ['crab', 'apple', 3, 'foo'], @oh.values
   end
 
+  def test_inspect_retains_order
+    assert_equal '{"c"=>1, "a"=>2, "z"=>3}', @oh.inspect
+  end
+
 end