Lovato’s latest perfectly balances party jams with confessional ballads. By Jocelyn Vena Demi Lovato Photo: FilmMagic Instead of going too edgy or staying a Disney princess, Demi Lovato’s Unbroken, which drops Tuesday, is a perfectly mature album without scaring away the teens that grew up loving the “Camp Rock” star. Thanks to touches of Gwen Stefani, Christina Aguilera and Beyonc
