Shorten timestamp for received messages to not include timezone or year.

It annoyed me that half the width of my terminal was being repetitively
used to tell me way too much info about the time a message was received.

 * CHANGES the format of timestamps prepended to received messages to
   not include the timezone or year, i.e. "Mon Jan 02 15:04:05".
Use standard timestamp for messages.
Merge branch 'shorter-timestamps'