Remove superseded SelectionMover class

The SelectionMover class has been superseded by more flexible combinations of filters, scanners and utils. The replacements bring less dependence on the cursor node for positioning, allowing greater flexibility and re-use.

Removing this code and associated tests performs the final step necessary to close #224. In addition, this eliminates redundant line detection logic, so #225 is also closed by this as well.
I posted the gist so you could doubt my own claims and do your own research ;-).

From the play I did, indexOf is never faster, and gets significantly slower quite fast. AND considering 99.9999% of the nodes matched in the document WILL NOT MATCH the filter, that means that usually indexOf has to walk the entire array length in order to determine that it has been given a non-matching node.

That seemed like a very strong reason to avoid indexOf to me.