(FR #1279) Preserve message headers when rejecting and requeuing

Change-Id: I6cb4e69342498ca9a33cbecc23791318892ac4c9
New schema for transaction source metadata

Change-Id: Ib820f16ab8dad2c6570c9c3d8f37cb342f6c3cf8
debug logging to diagnose FR #1267

Change-Id: I0d0940a5e83769affd618b9c6ec13bb8c07888ac