manual: get rid of the lists of packages

We currently have four lists of packages in the manual:
  - the non-virtual target packages,
  - the virtual target packages,
  - the host packages,
  - the deprecated features.

Those list take more than half of the manual. They do not serve much
purpose except to show off.

After the recent discussion on the list [0], remove them all.

We can now get rid of our biggish and complex generating script (and its
companion library kconfiglib).

[0] http://lists.busybox.net/pipermail/buildroot/2016-September/171199.html



Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>