Fix #162 - Flexible width is width="100%" is applied as attribute to the HTML table

- Attach an event handler to the window to resize the table. Note that
  this isn't debounced - possibly it should be in future(?), but don't
  want to add the additional code required if it isn't required. It
  seems to function perfectly well for me!

- Unbind needs to unbind by the instance unique reference since there
  might be multiple tables listening for the event.