use consistent read for reload

This changes document.reload to use a ```:consistent_read => true``` by default. I cleaned up the tests a little too.

The document ```.reload``` method is used when you have a record and want to load it again, typically to refresh the attributes. Without this patch, the problem is that ```.reload``` could be inconsistent, and actually not pick up recent changes. I could not think of any use case where you want to reload in in an inconsistent manner. Records can still be found with a ```:consistent_read => false``` using the ```.find``` method, however that is not intuitively what ```.reload``` should be doing and that is why I did not make it an option.