Allow LRGSlice in fetch_all_by_Slice_constraint().
Allow LRGSlice in fetch_all_by_Slice_constraint().

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