start of SliceFactory - stubs for new_slice and new_web_slice
start of SliceFactory - stubs for new_slice and new_web_slice

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