Sydney Morning Herald: There was a time when supermarket dockets were but fiddly bits of paper that were carelessly crumpled and thrown away. But a strange thing is happening at checkouts across the country. People are receiving their dockets gratefully, folding them carefully, and saving them to claim a four-cents-a-litre discount on petrol. Soaring fuel prices have transformed the humble supermarket docket into hallowed relief from record oil prices. The high price of oil is changing consumer behaviour …