[WIP] remove rewind

Old PR #91.

Closes #80

How can you know that it points to first element? The `proxyMe` method always returns 1, so you might as well be pointing to the 2nd element :smile:

For that reason I recommended to have 2 NodeElements in collection with different xpaths and then assert their xpaths instead. By the way you can drop `->getObject()` part, because end user shouldn't be using it at all.