LOS ANGELES (Reuters) - Have a "white girl problem" and don't know where to turn? Babe Walker, Twitter's snarky, self-obsessed socialite has produced the definitive guide on how to deal with life's trivial issues in a new novel out this month. A lot of work has gone into producing the "White Girl Problems" brand. What started as a phrase coined during an alcohol-fueled conversation one night in 2010 between friends, quickly became a business plan as brothers Tanner and David Oliver Cohen and friend Lara Schoenhals realized they had a viral trend at their fingertips. ...