The previous method was to use a custom install procedure, which
is a bit complex when automake can handle this for us, and as a
side effect it made 'distcheck' fail on uninstall procedure check.
The new method is to use a simple conditional and autoconf/automake
will do all the work for us.
Signed-off-by: Christophe CURIS <christophe.curis@free.fr>