Proposal to have optional confirmation dialog on row delete

I just finished implementing delete with a confirmation dialog - which I think is still considered best practice - and it was a bit clunky with the current implementation of `onRowsDelete`.

I had to grab the selected elements and return false from `onRowsDelete`, then fire the dialog and on confirmation, pass the selected indexes up to the controller via callback for removal.

Would you be open to a pull request that would allow the user to either request or provide a confirmation dialog on delete?