Log inability to find tag info for a message as info rather than error since it can happen once per message currently if a conversation is prematurely closed. Leave TODO to log it as an error (this code might not survive the new endpoint routing anyway).
Fix typo in fallback delivery_class type.
Rather fall back to original transport type in transport type isn't one understood by Go currently -- this at least generates useful errors (review by @jerith).
Merge branch 'develop' into feature/issue-186-stop-double-confirmations