Added -setrelease parameter.
Added -setrelease parameter.

Improved usage docs.

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