The code converting maximal cliques to coalitions of CL is now much more
readable.

As ocaml is not purely functional, the following code snippets have
different semantics:

    List.map (List.fold_left tmpf (bsetMakeRealEmpty ()))
             (List.map S.elements intlist)

vs

    List.map (fun x -> List.fold_left tmpf (bsetMakeRealEmpty ()) x)
             (List.map S.elements intlist)

The former code calls bsetMakeRealEmpty only once, but the latter calls
ot for each element of the list returned by the (map ... intlist).

Because of this, all coalitions were merged into one big set, i.e.
there always was only one coalition: the union of all maximal disjoint
sets. This of course triggered bad behaviour, which is fixed now by this
commit.

The code is unreadable anyway and will be improved a lot by the
following commit.

This closes #13

Insert a formula into a bitset without checking for a contradiction. The
former addBS performed a contradiction-check using MiscSolver.arrayNeg
which is a array of size 0 due to not being initialized.

For some reasons this bug only could be triggered when building with
oasis and not with the old Makefile, though arrayNeg being of size 0 in
both cases.

This fixes #12.