We ignored conflicts/obsoletes during pool preparation as it got
into the way of finding supplements (due to conflicting packages in
the list). But this way, conflicts were invisible also during dependency
search, leading to wrong packages picked for the package lists in
general.
So add a flag to prepare_pool to explain if we want conflicts or not
There is no product that wants all suggests for all products on all groups,
so the only product left that wants to have suggests is Tumbleweed for the DVD
pattern
To solve the suggests we run a global transaction on the
result + its suggests to determine packageand supplements.
To avoid problems (in general) we discard obsolete and conflicts
in packages - so we can have product groups with conflicting packages
and still get the additional supplements
