LOS ANGELES (Reuters) - Canadian rockers Avril Lavigne and Nickleback frontman Chad Kroeger are engaged to be married, Lavigne's spokeswoman confirmed to Reuters on Wednesday as news of the impending nuptials spread online. People.com reported that Kroeger, 37, proposed to Lavigne, 27, on August 8 with a 14-carat diamond ring. The couple fell for each other while working together on Lavigne's fifth studio album. No wedding date has yet been set. ...