lei: dump errors to syslog, and not to CLI

lei: dump errors to syslog, and not to CLI

Dumping errors from the previous run can often get lost, so just
spew to syslog since it's a standard place to put errors that
don't make it to a client.  Note: we don't rely on $SIG{__WARN__}
since some of the Net:: stuff will write directly to STDERR
(as will external processes).