It appears that features.in/Makefile functioned a bit
differently by now than was described back then: after
loops and pushds got rearranged for robustness, it stopped
to pick up a cleanup feature tagged script.

That particular script is now better de-tagged and simply
placed as a script to be merged into install2 subprofile.

The tagged scripts still require a bit more comprehension
to understand the use cases (e.g., do we need per-subprofile
tagged script subdirs or just a toplevel one should be looked
at, with script names telling where to put them).

README used to mix up subprofiles and features; fixed.