Added an option to specify the location of the pfetch binary file.
Added an option to specify the location of the pfetch binary file.

james-monkeyshines/ensembl-analysis,kiwiroy/ensembl-analysis,Ensembl/ensembl-analysis,Ensembl/ensembl-analysis,mn1/ensembl-analysis,mn1/ensembl-analysis,james-monkeyshines/ensembl-analysis,mn1/ensembl-analysis,james-monkeyshines/ensembl-analysis,Ensembl/ensembl-analysis,kiwiroy/ensembl-analysis