Should DTPC be used?

The main reason we wanted DTPC was because were worried that data could be too large to fit in the SDR, but most email services tend to have limits on the MIME message size anyway, so this shouldn't be much of a problem anyway. Without DTPC, we also strip overhead and we don't have to deal with nondeterministic behavior for DTPC profiles (weird exit behavior like in #16 and needing to use larger ATL to avoid failing tests). Configuration would be simpler for users and we don't have to worry about topic IDs (see #26).