Provide information on (-) side domain boundaries
Presently, we provide information if a field is on a (+) side of the domain since some field types (face fields) get extra storage locations in that case. For variable-width stencils (high-order finite difference), we will need information on whether a field has a (-) side boundary as well.
Note that Wasatch will need to be modified to also provide this information to fields as they are created.