WINNIPEG (Reuters) – Canadian Prime Minister Stephen Harper wanted to talk about his promised diesel tax cut on Tuesday but found himself sidetracked by his Conservative Party's depiction of a puffin pooping on his chief rival. A Conservative website, http://notaleader.ca, showed an animated puffin flying across the screen and plopping a white blob on the shoulder of Liberal leader Stephane Dion, drawing an angry response from Dion and an apology from Harper. "It was tasteless and inappropriate. We have enough differences with the Liberals without getting into that kind of thing," Harper told a news conference after announcing he would...