Improving error documentation for methods which now throw errors
Improving error documentation for methods which now throw errors

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