New: `os` style row selection.

- TableTools now supports a fourth row selection option (in addition to
  none, single and multi) which is 'os' - Operating System like
  selection. This allows a range of rows to be selected by shift
  clicking, rows to be added and removed from the set using ctrl / cmd
  click and single row selection on an unmodified click.

- This feature was sponsored by Mangosoftware UK Ltd
Examples: Add os style row selection to examples