makes conversations for received messages, insufficiently tested
Merge branch 'master' of github.com:andres-erbsen/chatterbox
Merge branch 'master' of github.com:andres-erbsen/chatterbox
Merge branch 'master' of github.com:andres-erbsen/chatterbox
Merge branch 'master' of github.com:andres-erbsen/chatterbox
Merge branch 'master' of github.com:andres-erbsen/chatterbox
Merge branch 'master' of github.com:andres-erbsen/chatterbox
Creates conversation directories for received messages

also names files correctly w/ date-sender.

also sends messages placed in existing outbox directories

conversation directories match across participants in a conversation but
i don't create the corresponding outbox directory yet