OptionalObsoleteFiles.inc completeness improvement, try 2

[Dmitry Marakasov]

Hi!

Some years ago I've started a project of improving
OptionalObsoleteFiles.inc completeness, which allows make delete-old
/ delete-old-libs / delete-old-dirs targets completelty remove files
which are normally installed when specific src.conf WITHOUT_* knobs
are set.

In other words, if a user has some WITHOUT_* set in src.conf,
specific files are not installed by installworld, but not removed
by remove-old, which I try to fix.

In yet other words, I want to make it so `make installworld
-DWITHOUT_foo=yes` and `make installworld && make delete-old
-DWITHOUT_foo=yes` result in the very same file sets.

Though the project seems to be useful and have real demand (added
to IdeasPage by netchild@, though removed later by brooks@ [1])
and interest ([2]), the change was ignored back then and now the
patch is completely rotten. I can redo it, but I need a reviewer.
Here's a first small part of the patch:

https://reviews.freebsd.org/D1600

The WIP branch with other changes is [3]

Also there is a question of delete-old-dirs removing directories
which are created by mtree run by installworld unconditionally.
This seems to be incorrect - either directories should be installed
conditionally or not removed by delete-old-dirs. My patch will
address this issue as well, by not remiving unconditionally installed
dirs.

[1] https://wiki.freebsd.org/action/diff/IdeasPage?action=diff&rev1=260&rev2=261
[2] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=168341#c6
[3] https://github.com/AMDmi3/freebsd/compare/obsolete-files

-- 
Dmitry Marakasov   .   55B5 0596 FF1E 8D84 5F56  9510 D35A 80DD F9D2 F77D
amdmi3 at amdmi3.ru  ..:  jabber: amdmi3 at jabber.ru    http://www.amdmi3.ru