Log Message:
Import dhcpcd-7.0.0-beta3 with the following changes:
  *  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.
  *  install udev.so on supported platforms to fix segfaults.
  *  support NetBSD's RO_MSGFILTER socket option to reduce avoid context
     switching for route(4) messages that don't interest us.
  *  support OpenBSD's ROUTE_MSGFILTER which does the same.
  *  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.