Starting with tag: [TAG 0.5.7 Conal Elliott **20090503213934] [compare method; cosmetic tweaks Conal Elliott **20090629191003] [comment Conal Elliott **20090629191825] [fixed recip deriv. Thanks to Yrogirg Conal Elliott **20100316200846] [releasing version 0.5.9 Conal Elliott **20100316200944]