New, improved version of 'ElectreTriClassAssign' module (under the new
name 'ElectreTriClassAssignments') - it has better assignment routine,
works with outranking relations produced by 'cutRelationCrisp' module
and generates separate outputs for 'conjuctive' and 'disjunctive'
assignment procedures.

Some improvements in 'common.py' - mostly in getting the input data.