class dbcClusterFileReader: this object extract and store the information given by the dbc software output. Unlike cd-hit output, dbc output do not provide a cluster head (a sequence that will be the representant of the cluster), so this sequence will be chosen as the one beeing the most frequent in each cluster. As the clusterID is the seqID of the cluster head, the clusters are instanciated with a temporary ID (number) and this ID is changed when the file is read and the clustersID are known.