added hack to not return AlleleFeatures if StrainSlice is the fake reference one
added hack to not return AlleleFeatures if StrainSlice is the fake reference one

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