suggestion: hook for pkg_add is needed

[Aleksey Cheusov <cheusov%tut.by@localhost>]

Sometimes when a package is installed it is necessary to do some
additional actions. I personally whould like to postprocess MESSAGE
content (collect, email or something similar), to change permissions
for SUID executables or anything else.

I think it whould be nice to have an optional external program which
is run at installation stage and have binary/package_name/anything_else
as its argument.

Is this suggestion good enough for change-request/PR?
Can anybody implement this feature?

-- 
Best regards, Aleksey Cheusov.