clarification to documentation for fetch_all()
clarification to documentation for fetch_all()

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