Add VMware VMXNET3 ethernet driver from OpenBSD, vmx(4).
Note vmx(4).
Fix static linking for the tests: -lrump is also used by -lrumpuser,
so we also need -lrump after -lrumpuser.  Fixes build for sun2.
Sort SEE ALSO, add NetBSD-specific history.
Introduce new sysctls for obtaining interface-specific addresses:
- net.sdl for the active link-layer adddress (the MAC)
- net.ether.multicast for the Ethernet multicast addresses
- net.inet6.multicast for the IPv6 multicast groups
- net.inet6.multicast_kludge for temporarily removed multicast groups

Use this sysctls for replacing the kmem grovelling in ifmcstat(8).
Reflect reality.
Add missing Nm section which was breaking makemandb indexing of the man page.
From Abhinav Upadhyay.