etc/Makefile cleanup

[Matthias Schmidt]

* Simon 'corecode' Schubert wrote:
> 
> >I also added a short message and a 5 seconds delay to make really sure
> >that the user performed a "make installworld" first.  The message and
> >the delay could be removed if somebody argues.
> 
> That's bad.  We should find a better way that a) relying on the user to prevent 
> the user from hurting itself and b) annoying the user.

Sascha suggested to install the FilesToRemove.inc with installworld to a
temporary location and have "make upgrade" use this file instead of the
one in the source tree.

	Matthias