Good news, penniless folk fans: badass Boston folk musician Mieka Pauley kicks off a national tour this week with three shows in Boston, and two of them are free. If you're not already down with Pauley, whose throaty, tough, stripped-down songs form the perfect counterpoint to the overproduced, overwrought studio stuff that passes for "folk" these days, this is your chance to check her out alongside some other talented acts. (Photo by Josh Rothstein)......