to both directories, and make it relative, rather than absolute.
This fixes the case where you might install the docs under one directory
/foo/bar/..., and then want to migrate them elsewhere (to /usr/share/).
With the old scheme, the symlink would start /foo/bar/..., and would
therefore be broken.
A good example of this happening is "make release" :-)
in the case of */FAQ/Makefile, because the FAQs are all in the wrong
place. Things still install properly, but some of the directory paths
are hardcoded. This will be going away ASAP.
