A couple of small updates and fixes. See details.

SMS is added to database after send from conversation (still not from
compose)
Inbox is refreshed on resume.
Most recent message in conversation is displayed in inbox whether it was
sent or received. Previously the most recently received message was
shown no matter what.
Messages sent from compose view added to db

Messages sent from the compose screen are now also added to the sent
messages database. Still need to see if this will work when a message is
sent from the compose screen to a contact with whom a prior conversation
thread does not exist. If not, a new thread and thread_id will have to
be created.