change DESTROY so that forked processes don't disconnect parent's db handle
change DESTROY so that forked processes don't disconnect parent's db handle

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