MFC: 266836, 266839

MFC: 266836, 266839
vt(4) support for vidcontrol(1).
  o Teach vidcontrol(1) how to load vt(4) font.
  o Teach vidcontrol(1) to distinct which virtual terminal system is running now.
  o Load vt(4) fonts from different location.
  o Add $FreeBSD$ tag for path.h.
vt(4) support for kbdcontrol(1).
  Enable kbdcontrol(1) to use maps from vt(4) keymaps dir /usr/share/vt/keymaps
  if vt(4) is present.

Sponsored by:	The FreeBSD Foundation

git-svn-id: svn://svn.freebsd.org/base/stable/10@267540 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f