Bio::EnsEMBL::DBSQL::DBAdaptor to match symetry with core,pipeline,compara
This means I can remove all 'hive' adaptors from compara now and the
URLFactory now returns by default a Hive::DBSQL::DBAdaptor.
This also means I can make my graph configuring runnableDBs really
adaptible to run on both Pipeline and Hive systems by doing
if($self->db->isa('Bio::EnsEMBL::Pipeline::DBAdaptor')) {...}
if($self->db->isa('Bio::EnsEMBL::Hive::DBAdaptor')) {...}