a00e51c - Log errors from the routine polling producers.

a00e51c - Log errors from the routine polling producers.
   Currently, they just go silently into the log file.  Furthermore, they
   currently *kill* the producer thread, so if one batched email fails, they
   all
   *stop* until one of us restarts the fedmsg-hub daemon.

   This change 1) logs errors and more importantly 2) leaves the producer
   running.

1b604db - Try to get encoding right with email messages.

   This works against the current bug that had the production instance backed
   up.