Removed useless includes.

Till the next bug.
Simplified generated BATs.
Implemented belief setups.
Added KBat, BBat classes for generated knowledge/belief BATs.
Fixed: assertion in Setup::PropagateUnits() to allow non-units.

Setup::PropagateUnits() loops over unit clauses using
lower/upper_bound(). It may encounter a non-unit clause in this loop in
case a resolvent in a previous iteration was non-unit and less then
*last where last is the upper_bound(). The new assertions respect this
case.

Also addded `scalable' unit tests for eventual completeness and
inconsistency.