Validations guide: order of :after_save callback was incorrect.

The guide was contracting itself. First it stated that 'there is a list
of callbacks in order of execution', on the list 'after_save' was placed
before 'after_create', and then there was a warning that 'after_save'
runs after them. I am not sure about 'around_' callbacks, but let's
leave that for another patch.

railties/guides/source/active_record_validations_callbacks.textile

@@ -912,20 +912,20 @@ h4. Creating an Object
 * +before_validation+
 * +after_validation+
 * +before_save+
-* +after_save+
 * +before_create+
 * +around_create+
 * +after_create+
+* +after_save+
 
 h4. Updating an Object
 
 * +before_validation+
 * +after_validation+
 * +before_save+
-* +after_save+
 * +before_update+
 * +around_update+
 * +after_update+
+* +after_save+
 
 h4. Destroying an Object