document the Target config option
remove useless autoconf files

they are not even needed.
if they were, autoreconf -i would create them just fine.
always call pcap_open_live() with a reasonable timeout

just because linux apparently does not support a timeout does not mean
that we should pass a value that would result in a livelock if it did.
remove some pointless linuxisms
de-duplicate ethernet handling code

just compile as BSD source. works with (e)glibc and uClibc (apart from
real BSDs), so this should be good.
don't crash if we get an unexpected link layer header
DLT_LINUX_SLL doesn't make sense outside linux