Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

- Don't include opt_global.h, it is always included implicitly.
- Include opt_device_polling.h

Oops, left a compile option enabled that should not be enabled.

Reintroduce the lmc T1/E1/T3 WAN driver. This version is locked, supports
interface polling, compiles on 64-bit platforms, and compiles on NetBSD,
OpenBSD, BSD/OS, and Linux. Woo! Thanks to David Boggs for providing this
driver.

Altq, sppp, netgraph, and bpf are required for this driver to operate.
Userland tools and man pages will be committed next.

Submitted by: David Boggs