The previous commit (r269119) introduced a regression: It removed the
ability to specify the the full path name of the keymap file.

Instead leave the original search order intact, but insert the path for
newcons-specific fonts (if run on a system using newcons):

	- KEYMAP_PATH in environment
	- full path name
	- /usr/share/vt/keymaps		(only if newcons is in use!)
	- /usr/share/syscons/keymaps	(also as fall-back for newcons)

MFC after:	1 week