Bug#586434: Let's clean the apt cache

[Petter Reinholdtsen <pere@hungry.com>]

[Frans Pop]
> The only reason I see to keep the cache is when some packages (after 
> base-installer) fail to install. If we want to cover that case it should 
> be detected automatically by testing the result of tasksel [1]. The final 
> cleanup could be omitted in that case.

Sound like a good idea.

> [1] Checking installation of packages using apt-install is much
> harder to do as there are many different calls and failure may be
> expected in some cases. It also gains much less as their total size
> is much less.

I believe it would not be very hard.  We would have to add code to
apt-install, and to the udeb handling the queue updated by apt-install
before base-installer is exeucted.  No need to update all those
calling apt-install for this.

Happy hacking,
-- 
Petter Reinholdtsen