added some more heuristics to external_db.db_name query
added some more heuristics to external_db.db_name query

at7/ensembl,Ensembl/ensembl,mjg17/ensembl,james-monkeyshines/ensembl,willmclaren/ensembl,mjg17/ensembl,at7/ensembl,danstaines/ensembl,Ensembl/ensembl,at7/ensembl,mjg17/ensembl,Ensembl/ensembl,danstaines/ensembl,danstaines/ensembl,muffato/ensembl,james-monkeyshines/ensembl,muffato/ensembl,Ensembl/ensembl,willmclaren/ensembl,james-monkeyshines/ensembl,james-monkeyshines/ensembl,at7/ensembl,muffato/ensembl,mjg17/ensembl,muffato/ensembl