Add the "Lead is deleted from Dynamics" Trigger

This trigger exists in Marketo for SFDC, but not for MS Dynamics.

It enables Marketo to react to a contact or a lead deletion in MSD (for instance to also delete the lead in Marketo and avoid it to reappear later on).

The lack of this functionality, combined with this other idea : creates a significant data management issue.

Of course, we can run a daily batch, using the "Microsoft is Deleted" filter, but it's not reactive enough: so many things can happen in 1 day

-Greg