branches: 1.1.2;
Add shmif_pcapin(1) utility program

It can send any frames that are stored in a pcap(3) file format to
shmif(4) Ethernet interface via the bus of it. If you want to write
some tests for networking with rump kernels and the tests need to send
frames that are difficult to generate by stock programs, shmif_pcapin
can be helpful.

The author of shmif_pcapin is k-goda@IIJ and the man page is written
by ozaki-r.