An initial (and quite naive) implementation was done
for conf.d/ files but features do need it as well --
which became obvious during a casual inspection of
distro/alt-workstation's target graph (which occured
broken).

The code is a messy hackery unfortunately, regexes used
are fragile regarding e.g. [A-Z_] in target names.
Read with care.

NB: lib/ might need this too but it's rather stable
    and contains some special cases that would obstruct
    the regexes even more...