synapsestudios/synapse-base — pull request #113 by synbot (2014-08-26 22:36:23+00:00)
Title: Modify Validation Constraint RowExists

## Modify Validation Constraint RowExists, Add RowNotExists

### Acceptance Criteria
1. `RowExists` validation constraint is modified to allow overriding the field searched.
1. Default is still `id`, retaining backwards compatibility.

### Tasks
- Modify RowExists and RowsExist fields.

### Additional Notes
- None