C2MS12 — Cleanup of Message Summary Tables

Table 8-15 Archive Message Retrieval Request Summary has the first column centered. It's the only one of this type, all others of this type use left-justified, so that needs to be corrected.

Additionally all these tables throughout the document use "Senders Intended Usage" and "Receivers Intended Usage". These should be "Sender's" and "Receiver's" respectively. Or maybe Senders' or maybe we just say "Intended Usage for Senders" They all have to change anyway, so this might be the best form.