ifmedia changes:

ifmedia changes:

- Extend the number of available subtypes for Ethernet media by using some
of the ifmedia word's option bits to help denote subtypes. As a result, the
number of possible Ethernet subtype values increases from 31 to 511.

- Use some of those new values to define new media types.

- lacp_compose_key() recgonizes the new Ethernet media types added.
  (Change made as required by a comment in if_media.h)

- New ioctl, SIOGIFXMEDIA, to handle getting the new extended media types.
  SIOCGIFMEDIA is retained for backwards compatibility.

- Changes to ifconfig to allow it to handle the new extended media types.

Submitted by:	mike@karels.net (original), hselasky
Reviewed by:	jfvogel, gnn, hselasky
Approved by:	jfvogel (mentor), gnn (mentor)
Differential Revision: http://reviews.freebsd.org/D1965