Refactored counters, batch job trigger adjustment, all recipient types i...

- Counters are now an array, to make it easier to check and update values. 
- Batch sending now triggers on 1,000 recipients of any type (to, cc, bcc)
- Exception will be thrown in Message Builder if any recipient type exceeds 1,000. (Use a batch job instead)
- Recipient variables are added to the batch job, regardless of recipient type.
- Tests for all the above.
- Fixes #17