Major flaws of the new make deinstall code

[Maxim Sobolev]

Folks,

I've noticed several misbehaviours of the new make deinstall code,
particularly:

1. The new code behaves incorrectly when there are several @cwd
statements in the packing list. Particularly, it affects many
ports from games category, which usually create files and dirs
under /var. For some reason, make deinstall code takes the second
@cwd as the prefix of the installed package and obviously mismatch
happens. This needs to be corrected ASAP.

2. In general, prefix-safety feature of make deinstall is misdesigned,
as it should not reject deinstalling package which has no dependants
(i.e. packages that depend on it) regardless of its prefix, as
replacing this package with one with a different prefix will not
lead to any problems I can think of.

-Maxim