Internal: Change the application of global filtering methodology

- Reducing the complexity of how the global filter is applied in
  DataTables by removing the `asDataSearch` internal settings array
  which held information about each row's filtering data. This is now
  held on a per row basis in `_sFilterRow` which is built only when the
  data is invalidated. This should result in a small performance
  improvement as well as simplifying and reducing the code.

- Filtering is now implemented by simply checking the built regex
  against the `_sFilterRow` parameter for the display array (with a
  reset to master, as there was before, if needed)

- This also fixes an indexing issue that was present in the filtering in
  1.10.dev only