Cleaning obsolete files after make installworld

[Luís Fernando Schultz Xavier da Silveira]

Hello,

> Check out the /usr/src/Makefile, particularly the # check-old and the # 
> delete-old sections. I've never found a need to use these, so I really am 
> uncertain how they would be used. But it seems as if they might come into 
> play after a make buildworld but prior to a make installworld. I could be 
> very wrong about that. But if you can track down how to actually use these 
> targets I think it may remedy the problem.

I did use the delete-old functionality. The problem is the files persist
even after that.

The delete-old command does not seem to take into account software that
was disabled in /etc/src.conf and needs to be removed.