Fix issue #17

I also ran into the issue reported in issue #17.  My fix is nearly identical to the one proposed by Pascal in the comments for issue #17.  The code now wires up spring dependencies into the newly created validatable object before doing the validation which is what would normally be the case for a command object on the server side.  Also, it checks to see if the object is a domain object or not before calling isAttached() on it since isAttached() won't be present on command objects.  It looks like maybe Pascal never sent you a pull request.  Can you please pull this fix in?