added cache_and_load method to prevent memory errors with unmapped object cache
added cache_and_load method to prevent memory errors with unmapped object cache

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