We leave the files in the hands of the local admin if they seem to be
used. We're working under the assumption that most people use
console-setup, but that is not a hard requirement on Debian so we don't
want to yank the carpet under the feet for potential users of the kbd
script.

The package installs a symbolic link and a file with the same name in
both /bin/ and /usr/bin/, so it makes impossible to convert a system
to the everything-in-usr directories scheme.

This solves the problem by creating the link in postinst and only if it
is needed.

For more information about everything-in-usr please read
http://anonscm.debian.org/cgit/users/md/usrmerge.git/tree/debian/README.Debian

Closes: #767922