* restored --logfile support as a few people complained it vanished
The new logging code even makes the overall binary size smaller
on most platforms.
* BPF filter now trims garbage trailing the payload
OK, it's not garbage, but userland doesn't know some drivers append
FCS to it.
* support NetBSD's RO_MSGFILTER socket option to reduce avoid context
switching for route(4) messages that don't interest us.
* Don't open sockets if just sending signals.
* HMAC-MD5 test's now check expectations in code rather than relying
on visual confirmation.
* added eloop-bench to test performance of eloop with available
polling mechanisms.
