[pkg-fso-maint] tasks for install.sh

[Steffen Moeller]

Hello,

we agreed that there should a preparation for tasksel to help with a group-install and
configuration of packages. As a basis for a discussion about what these tasks should look
alike, I have added the notion of tasks to the install.sh script. The games target and the
--with-wifi option had to go.

To specify the tasks that shall be addressed, the user now specifies the environment
variable TASKS, as in
export TASKS="GPS,WIFI,GAMES"
then runs install.sh either with the all target (as before) or, if only the tasks shall be
worked on, with './install.sh tasks', with tasks being the target that previously was 'games'.

The program has a set of variables declared that know about the packages that are
associated with the tasks. It will take another few days until WIFI will work because of
the wicd issue. But this is being addressed by the package maintainer / buildds  while I type.

./install.sh --help gives further details on how to use the tasks.

Enjoy,

Steffen